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NASA

CLASSROOM

TRAINING

Prepared

HANDBOOK

under

Contract

Convair General

NATIONAL

George

C.

NAS 8-20185

Diego,

Marshall

AERONAUTICS

TESTING

by

Division

Dynamics San

for

- RADIOGRAPHIC

CR 61231

Corporation Calif.

Space

Flight

AND SPACE

Center

ADMINISTRATION

_N 68 - 20 79 3 (ACCESSION NUtVIBER)

(PAOES)

CTHRU)

{C/ObE)

/5(_

GPO

PRICE

CFSTI

$

PRICE(S)

$

Hard copy (HC) Microfiche ff 653

July 65

(M F)

CR OR TMX OR AD NUMBER)

(CATEGORY)

V

PREFACE

_._s_oom training

Training handbooks

Handbook-designed for

of/t_ondestructive of those persons

Testing. who have

Although

formal

classroom

contains

material

NASA's

programs

that

Radiographic Testing use in the Classroom

It is intended that this handbook successfully completed_I_z_grammed

training

is not

is beneficial

involve

tightly

This

approach

to _l_ondestructive

A major with

share

NASA,

sonnel.

requirement

of the

other

These

or reject room for

are

each error

scheduled

--

technical

George C. Huntsville, The recipient and comments

Government

Marshall Alabama

the

time,

this

_-

handbook

infl_ondestructive/T_sting.

procurement

of only

requiring the of one article

reliability

for

first

small

quantities

of

extreme in reliability for could result in mission

necessitates

a thoroughly

disciplined

such

high

levels

of reliability

and contractor_l_ondestructive

who conduct

or

monitor

before it is committed reexamination. The

the

tests

to its decision

lies

T_sting that

ultimately

perconfirm

mission. There is no must be right --

time.

questions

concerning

Space Flight 35812.

Quality 35812.

assuring

agencies,

people

of this handbook for correction

Space Flight Center, Huntsville, Alabama

present

instruction Handboot_

?]_esting.

responsibility

the

be used in the Instruction

at the

eng_aged

equipment, The failure

complete

piece of hardware -- no chance for

unquestionably General

for

scheduled

to personnel

space vehicles and ground support the first as well as later models. failure.

(5330.19) is one of a series of and practical exercise portions

this

Center,

publication Quality

should

be referred

and Reliability

Assurance

to the Laboratory,

is encouraged to submit recommendations for updating of errors in this initial compilation to George C. Marshall and Reliability

Assurance

Laboratory

(R-QUAL-OT),

v

ACKNOWLEDGMENTS

This

handbook

under

NASA

reviews, The

prepared

Contract

following

other

advice

listing

for

the

by the

Convair

NAS8-20185.

and technical

gratitude and

was

Assistance

was

provided

is an attempt

high

individuals

degree

In many

of General

in the

form

by a great

to acknowledge

of interest

who,

Division

exhibited

cases,

and

technical individuals.

and to express

firms,

considerable

Corporation

data,

companies

assistance

by the

gave

of process

many

this

Dynamics

their time

our

representaiiw's,

and effort

to the

X-Ray

Co. ;

project. Aerojet-General Automation Wilcox Division; Kodak Grumman

Corp.

; Agfa-Geveart

Industries,

Inc.,

Electric

Corp.

Douglas

Aircraft

Co.,

Radiography

Aircraft;

Aircraft

Corp.

Phillips

Electronic

; C.

H.

F.

Corporation;

Cancer

Center;

Southwest

Operations,

Inc.

; E.

Muller

Division; Corp.

Picker

Richard Research ; Uresco,

; The

Institute;

St.

; X-Ray

Budd

American

; Professor

Rontgenwerk; Testing

Products

Babcock

&

Instruments Inc. ; Eastm:_n

& Film

Coo (Denver);

North

Louis

Co.,

& Co.,

Analine

Martin

Corp.

& Co.

Corporation;

De Nemours

Rontgenwerk;

Setfert

The

General

X-Ray

Inc.

Avco

Company;

I. DuPont

Gmbh,

Inc. ; Aircraft

Division;

Boeing

Aircraft

Instruments;

; Rohr

; The Inc.

of America,

Products

Markets

Lockheed

L.S.U.

Technical

Sperry

Co. ; Balto

Company,

Co.

Corp.

L

V

;

McDonnell Aviation,

l_c.

tlarry

Richarcison,

Southern

California

Laboratories,

Inc.

:

Corp.

V

ii

J

CLASSROOM

TRAINING

RADIOGRAPHIC

HANDBOOK. TESTING

CHAPTER 1

.......................................

CHAPTER 2

.........................................

PRINCIPLE

CHAPTER 3

.........................................

EQUIPME

CHAPTER 4

..............................................

CHAPTER 5

............................................

CHAPTER 6

............................

CHAPTER 7

.............

INTRODUCTION S NT FILM SAFETY SPECIALIZED COMPARISON

AND

SELECTION

APPLICATIONS

OF NDT

PROCESSES

iii

w

CHAPTER

1:

TABLE

INTRODUCTION

OF

CONTENTS

Page

Paragraph I00

GENERAL

i01

PURPOSE

102

DESCRIPTION 1. 2.

............................

OF

CONTENTS

1-3

.........................

1-3

Arrangement ................................. Locators ....................................

103

INDUSTRIAL

104

BASIC

105

ADVANTAGES

106

1-3

...................................... ...........

APPLICATIONS

RADIOGRAPHIC AND

1-3 1-4

OF RADIOGRAPHY

TESTING

............

1-4

LIMITATIONS

....................... OF RADIOGRAPHIC

1-4 TESTING..

1-4

1.

Advantages

..................................

1-4

2.

Limitations

..................................

1-5

DESTRUCTIVE

AND

1.

General

2.

Nondestructive

NONDESTRUCTIVE

TESTING

....................................

107

TESTING

108

PERSONNE

109

TE STING

ii0

TE ST PROCE

III

TEST

112

SAFETY

Test

PHILOSOPHY

Methods

......................

.............................. ................................

DURE S ................................

OBJECTIVE CONSIDERATIONS

1-5 1-5

L ..................................... CRITERIA

...........

1-5 1-6 1-6 1- 6 1-6 1-6

...........................

1-7

p_C_DING

PAGB BLANY-- NOT, I:II..I_D_.

CHAPTER 100 The

complexity

and

that

Nonde structive radiography

i01

PURPOSE purpose test

quality

of the

102 1. The

¢

results require

ARRANGE

without

retest

associated

provide

methods

and

inspection

ground

s many

test

equipment.

of the se procedure

of nondestructive

testing,

and

s.

it is

is concerned.

the

or assistance

them

is being

evaluate,

and

knowledge

to enable

of techniques,

interpret, test;

fundamental

personnel

or combination

radiographic

fabrieation

and

de stroying)

effective

and test

product;

dictate

vehicles

is to provide

assurance

finished either

programs

of space

handbook

handbook

technique, of any

most

this

DESCRIPTION

material

(te sting

that

by quality

of space

reliability

of the

of this

proper

that

insure

is one

with

required

expense

te sting

Radiography

the

INTRODUCTION

GENERAL

procedures

The

1:

and

recognize

those

to.

used

make and

ascertain

that

to assure

a sound

areas

in interpretation

of radiography the

decision

of doubtful

the

test

as to results

evaluation.

OF CONTENTS

MENT

contained

in this

handbook

is presented

in a logical

sequence

and

consists

of: a.

Chapter

1:

Introduction

b.

Chapter

2:

Radiographic

principles,

description

c.

Chapter

3;

Radiographic

equipment,

industrial

ment, d.

Chapter

4:

and

gamma

Radiographic required

Chapter

5:

Safety

f.

Chapter

6:

Specialized

Chapter

7:

sources,

film,

and

of X-

and gamma

X- and gamma equipment

characteristics

considerations,

arrangements

g.

ray

philosophy.

ray

rays. equip-

description.

of film,

film

processing

and

equipment.

e.

and

testing

a listing

Comparison

X-ray,

applications, of specimens of possible and

selection

gamma

exposure and causes

ray,

and

electrical.

calculations, X-

or gamma

of unsatisfactory

of NDT

physical ray

equipment, radiographs.

processes.

1-3

2.

LOCATORS

The first paragraphs, 103

page

INDUSTRIAL

Because

of the

radiography such

of each chapter consists of a table of contents for the figures and tables are listed in each table of contents. APPLICATIONS

penetration

is used

as welds,

castings,

a variety forgings,

capabilities

of non-metallic and

fabrications.

of X-

and gamma

products,

and

Since

104

in use BASIC

of revealing

in a variety nondestructive

of distest

testing

TESTING

usually

requires

exposing

a specimen,

processing

radiograph. of any test

There are is dependent

many variables in these upon understanding and

the requirements discussed in this 105

ADVANTAGES

1.

ADVANTAGES

for, and the handbook. AND

the

film

penetrated

exposed

variables

film,

and

interpreting

rays the

procedures and successful control of the variables.

concerned

LIMITATIONS

to X- or gamma

with,

radiographic

OF RADIOGRAPHIC

that

have

resultant completion Details of

testing

are

TESTING

V

Some of the advantages are as follows:

1-4

products

today.

RADIOGRAPHIC

Radiographic

radiation,

metallic

it is capable

discontinuities (variations in material composition, or density) similar materials, radiographic testing is one of the primary methods

Major

OF RADIOGRAPHY

and absorption

to test

chapter.

of radiographic

a.

Can

be used

b.

Provides a permanent when desired.

c.

Reveals

d.

Discloses action.

e.

Reveals

the

with

internal

fabrication

structural

most

testing

as a quality

assurance

procedure

materials. visual

nature

image

record

of the

test

specimen

on film

of material.

errors

discontinuities

and

often

indicates

necessary

and

assembly

errors.

corrective

2.

LIMITA

There

are

TIONS

both

Geometric on specimens

spected are

and

specimen in the

film

cannot does

often

undetected

the

present

the

of the

suspected

tion.

Compliance

graphic

with

and testing

economical rates

that

require

106

chipped

tested or broken

destructive

testing that

testing,

testing

2.

can the

the

suspected

be oriented greatest

beam.

con-

as a limitatesting,

is time

practices.

Radio-

testing. of simple

to examine

to

dimension

Safety

be considered

material

it is used

therefore,

It is most geometry

thick

with

specimens

potential.

test

methods liquid

TESTING

a certain

the

TEST

of nondestructive

of nondestructive method may

and test, will

and

are and

capabilities

method

only

determines

eddy

methods

testing,

of all articles

penetrant;

test

test

remainder

NONDESTRUCTIVE

peculiar

one

The

of nondestructive

when

that

are

must

in radiographic

handled

AND NONDESTRUCTIVE

during

however,

mitting

which

energy

by destructive

be assumed

Five

expensive

film

rays.

differ-

are,

discontinuities

and construction

means

density

be in-

discontinuities

discontinuities

radiation also

mandatory

easily

small

Similarly,

GENERAL

Specimens

cle;

must

utilization

to inspect

of high

DESTRUCTIVE

i.

space

to the

use. cannot

by material

type

to the

use

regulations,

It becomes

equipment

be parallel ray

is of little

and the

density

expensive

it is used

of test.

If laminar specimen,

testing source,

accessibility

in detecting type

testing.

radiographic of radiation

testing

Laminar

gamma

costly

is a relatively

when

high

must and

orientation

patterned

value

the

of radiographic

to two-side

are

of little

discontinuity

safety

requires

readily

testing.

discontinuity

use

to use

radiographic

itself

source,

by X-

proper

of radiation.

possible

imposed

consuming

lines

radiation

greatest

When

radiographs

are

by radiographic

in a specimen,

siderations

Since

to the

it impracticable

be obtained,

they

to the

limitations

make

not lend

method.

specimen,

not parallel

economic

geometry.

which

by this

ences

and

requirements

of complex

specimen, any

physical

exposure

quality

become

bent,

for

further

worthless of the

in quality that

articles

to those

of a specimen

materials

are

twisted, use.

notched, Consequently,

fabricated

tested.

without

and

it must

Nondestructive

destroying

it,

per-

to be used.

METHODS testing

currently and

qualifying

it is necessary obtain

are

ultrasonic;

limitations

be required.

are

portion

equal

current;

best

usually

the

it for

to analyze desired

in common

use:

radiographic. the

results.

specific test

magnetic

Each uses.

specimen In many

In each and

instances

parti-

method

has

instance

determine more

than

107 The

TESTING PHILOSOPHY basic

reason

of the

space

cated

of many

sponsible

for nondestructive

vehicle.

Since

articles

personnel

reliability.

that

the

up to these

standards.

108

PERSONNE

L

It is imperative

that

personnel

highly

with

a technical

(specimen),

equally tests for

and

qualified. must

continually

TESTING

When

required

tested

using

building

applicable test

Nondestructive

test

assurance

they

are

required

the

required must

be trained the

personnel There

of re-

results

and

item

under

must

NDT personnel

be

conducting

is no substitute

specimen,

review

formation

available

personnel performed,

conducting and that

to perform

for of past

history,

item

which

earliest

concerning

testing

support

article

must

The

criteria

is part

of a

must are

Using possible

are

experience

be tested

In turn

this

approach, resulting

be

individually

tested

time,

similar

formulated

on like

specimen

or

be brought to the attention into revised procedures.

test

from

similar

defects.

or checking a test to insure that the test objective is accomplished.

individually unsatisfactory in higher

sys-

analysis

of the

specimens,

It is the

and

in-

responsibility

procedures Procedures

of responsible

test of

are adequately found to be insupervision

for

OBJECTIVE

1. The objective of radiographic liability by providing a means of:

b.

each

in assemblies. at the

radiographic

correct or inadequate must correction and incorporation

a,

techniques. that

and

PROCEuU_ES procedures

TEST

dictates

vehicle

in sub-assemblies

faulty articles are discovered reliability and reduced cost.

TEST

every

Testing

which

to perform

Approved

1-6

insure

equipment,

developments.

documentation,

philosophy

it is required

before

111

test

task

set

and

fabri-

CRITERIA by appropriate

block

before

Ii0

of the

are

results

testing

of radiography,

of new

equipment

radiographic

Quality use

been

%J

reliability

it is the

test

have

for

procedures. abreast

ground

radiographic

understanding

optimum

maximum

by radiography,

standards

responsible

test

keep

task,

is to assure

knowledge.

109

and tem

the

To make

tested

whether

this

(NDT)

and associated

readily

to determine

come

test

vehicle

are

To accomplish

qualified

testing

Obtaining Disclosing

a visual

image

the nature

nondestructive

of the interior

of material

without

testing

is to insure

product

re-

of materials. impairing

usefulness

of the

material.

c.

Separatingacceptable andunacceptable material in accordancewith predetermined standards.

d.

Evidencing errors in manufacturing processes.

e.

Revealing structural discontinuities, mechanical failures, and assembly errors.

2. No test is successfully completed until an evaluation of the test results is made. Evaluation of test procedures and results requires understanding of the test objective. 112

SAFETY

Because safety and

CONSIDERATIONS

radiation

cannot

regulations gamma

damage sonnel must TAKE

to, are

ray

be detected

is required. sources

adequately

be continually

Radiographic

generating

or destruction

of,

the

protected. aware

by any

of the

great cells

of the

senses,

NDT processes amounts

of living

RadiograpMc radiation

five

hazard

of radiation. tissue, test

require

compliance the

Radiation

so it is essential

and

and

strict

quality

cognizant

assurance of safety

use can that

with of Xcause per-

personnel regulations.

NO CHANCES.

C

1-7

CHAPTER 2: PRINCIPLES TABLE OF CONTENTS

w

i

Paragraph

Page

200

GENERAL

201

PENETRATION

202

GEOMETRIC 1.

203

...................................... AND

Film

Image

Sharpness

...............

Film

Image

Distortion

...........................

GAMMA

1.

General

2.

Radiant

3.

X-rays

4.

Gamma

2-3 2-4 2-4

3.

X- AND

..........

...................

2.

RADIATION

. ...........

2-5 2-5

..........................

2-7

.................................... Energy

2-7

Characteristics

....................

2-7

.................................... Rays

Basic

Radiographic

Figure

2-2

Image

Enlargement

Figure

2-3

Image

Sharpness,

Figure

2-4

Effect

of Source

Figure

2-5

Image

Figure

2-7

Basic

Figure

2-8

Diagram

Figure

2-10

Effect

Penumbral Size

Figure

2-12

Figure

2-13

Ionization Internal

Figure

2-14

Side

Figure

2-15

Back

Figure

2-16

Dated

Shadow

on Image

.................

Sharpness

2-9

Inverse

Square

Voltage

Law

..................

on the

Beam

Quality

Decay

2-1

Effects

Table

2-2

Fundamental

Table

2-3

Gamma

and

in Tube

Current

2-11

on an X-ray

Beam

.....

2-12

...............

2-15 2-16

..................................

2-17

................................. Curve

of KV and Ray

2-10

.......................

by Electromagnetic Radiation Scatter ...............................

Scatter

2-6 2-6

of a Change

Scatter

2-5

..............

..............................

of an X-ray

Effect

2-3 2-4

of Increasing

2-11

.......................

Tube ..............................

of the

Intensity

2-17

Process

Distortion X-ray

2-8

.................................

2-1

Table

ABSORPTION

PRINCIPLE_

....................................

Figure

Figure

DIFFERENTIAL

EXPOSURE

General

2-3

.............................

2-19

MA ...........................

2-12

Particles Energy

2-17

.......................... •

•

•

•

•

•

•

•

•

•

2-13 !

•

•

•

•

•

•

•

•

•

•

g

•

a

•

•

•

•

2-20

2-1

V

pREEED|RG'PAGE

13,LAHK NOT

CHAPTER 200

2:

PRINCIPLES

GENERAL

This the

FILMED.

chapter use

provides

a general

of radiography

nature,

in industry.

but an understanding

201

PENETRATION

X- and

gamma

are

opaque

The

amount

of the matter means

rays

the

for

teristics

of radiation

through

at any

at that point; When this

penetration material

radiant

of the

point

energy

material

of the

phenomena

is basic

of penetrating matter,

materials,

some

is dependent

of these

upon

the

material

is available.

as used

in the

RADIATION

//

// //

C

process.

!

I I

\

\

\

are

those

in

that

absorbed.

and

emerging usually

Radiography

radiographic

even

rays

density

from the on film, a

consists

characteristics of radiant Figure 2-1 illustrates the

SOURCE

academic

thickness

the intensity of the rays is detected and recorded,

and differential absorption internal discontinuities.

and

permits

radiographer.

therefore, variation

the

that

ABSORPTION

capability

In passing

within

Much

DIFFERENTIAL

possess

of absorption

of seeing

of the

of it is required

AND

to light.

matter varies.

review

of using

the

energy to examine absorption charac-

The

specimen

absorbs

\

// !1 !1

\ \ \

//

\

II

\ \ \

Z z

// ///

/

\ \ \

SPECIMEN

\ \ \

/

\

/

FILM \

//

\\

//1

// ......... _.

\

/

1 / V01D\

\

I! / I I / I l I I I / I

\\

//

\\\

/

i

.....

I / /

/

\

L .t

/

# _"-"_L_.___.___

DARKER (WHEN

Figure

_v

AREAS

PROCESSED)

2-1.

Basic

Radiographic

Process

F

2-3

,radiation but, where it is thin or where there is a void, less absorption The the

latent

image

specimen,

Since

produced becomes

in the

more

radiation

passes

corresponding

areas

of the

202

GEOMETRIC

1.

film,

a shadow

through film

the

are

EXPOSURE

result

of the

of the

radiation

specimen

specimen

when

in the thin

passing

the and

film void

through

is processed. areas,

the

darker.

PRINCIPLES

GENERAL

To produce amined,

a radiograph and

geometric (specimen),

film.

there

Figure

relationships and the

lationships

are

ment

of the

image

ratio

of the

specimen

must

2-2

is a diagram

between film

caused

upon

the

diameter

the

specimen

and the

radiation

SOURCE

source,

rays

film

image

(do) to the size as the

laws

in contact diameter

as far

showing

under

is recorded. the

the

enlarge-

specimen.

The

to the

distance (df). film is placed the

film

re-

The

(Df) is equal

from

basic

examination These

of light.

with

to be ex-

ratio

For close

the to

as is practical.

\

/ /

\ \

/ SPECIMEN

image

exposure object

source-to-film specimen, the

is placed

S//'/"_

the

obeying

not being

(Do) to the

source

a specimen

of a radiographic

specimen

gamma

by the

of radiation,

radiation

which

by X- and

is caused

be a source

of the source-to-specimen distance radiographic image to be the same the

as the

picture

takes place.

\

I°

0 /_

!

IMAGE "__1

\

/

\

__

FILM _

-

Figure 2-4

Df

2-2.

Image

-

Enlargement kJ

2.

FILM

As shown the

IMAGE in Figure

radiation

film

SHARPNESS 2-3,

source

distance.

the sharpness

and the

Diagram

of the

ratio

of the

A shows

a small

film

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geometrical

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size

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o

F

F I

A B

A Figure the

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unsharpness,

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Figure

distance the

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DISTORTION

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from

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distance

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Film

EXPOSURE

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Ctirve

I I I I I I I I I I I I I

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2.5

ences, The

J

and

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H & D curves

increases,

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trast

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the

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exposure that

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films

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importantly, it is obvious

difference

in terms

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of film

film that

between density.

the For

con-

film two a low

exposure El, the difference in density between E A and E B is relatively small, and will probably not be discernible by the eye. By increasing exposure the

i

to the value

radiograph

between detectable contrast

b.

In industrial

a density

by the Film

of at least

light

intensity

speed

the

density

density.

High-speed more

radiography,

1.5.

available

is measured

requires illustrates

by E 2, not

but

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is the

difference

film

highest

desirable

for

reading

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exposure

needs to attain

H & D curves

for

should

The

by the

exposure

films

required

only low the

three

same

exposure film

different

speed

overall

density

(radiographic

E A and E B is greatly increased. The resulting by the eye. Selection of a correct exposure characteristics to amplify the subject contrast,

ful radiograph. for

represented

increased,

of

contrast}

contrast is easily has used the film's resulting in a usealways

density

to obtain while

the

be exposed

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a desired slow-speed

density.

Figure

films.

The

only

film film

4-4 shape

of

/ i 0

0.3

0.6

0.9

i []

Figure

4-4.

1.2 1.5 LOG RELATIVE

Relative

1.8 2.1 EXPOSURE

Film

2.4

2.7

3.0

Speed 4-7

each

curve

and

its

position

by the design of the since time is a cost considerations, used. Co

Graininess silver

film. factor

such

film Figure

4-5.)

(1)

The

fine

(2)

The

quality

crease

that

form

degree

or coarse of the

in the

graininess,

of the

and image The

exposure

axis

Film speed is a consideration in any industrial operation.

evidence

(grains) contrast

(See

log relative

as acceptable

is the visible

particles

affects

on the

grain

the

image

definition,

radiation

penetrating

to which

clumps

film

the

film film

may

of the film.

is subject

of any film

of the

quality

film

on radiographic

of graininess structure

fast

into

and all

V

of importance Whenever other

permit

grouping

is determined

be

minute It

to it.

is dependent

upon:

emulsion. Is exposed,

of the radiation

will

since

cause

an in-

an increase

in graininess. (3)

Film

processing,

ment

process.

because Under

in development (4)

The

use

increase

time

of fluorescent in radiation

graininess

normal

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conditions

is accompanied screens

related

of development

by an increase

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cause

to the

any increase

in film

increased

graininess.

graininess

energy.

COARSE GRAIN

FINE GRAIN

&

EXPOSED

UNEXPOSED

Figure

4-8

EXPOSED

4-5.

Film

Grain

develop-

UNEXPOSED

with

404

FILM

The

selection

certain

SELECTION of film

contrast

interrelated slow

films

have

graininess

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films

definition films

usually

fine

grain

and

1.

produced

usage

the

step

by the

resolution.

speed,

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been

made

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of a

graininess

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Film

designed

radiographs

resolution,

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radiograph.

are

for

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as possible,

in the

preceding

film

is limited

manufacturers

a specific

have

purpose.

Their

good

Use

c.

3.

within

In tank

of the

Equip

the

be processed All of the

processing step

those

so that

procedures

errors

in film

can

processing

the in-

make

an

is dependent

following.

the

following

general

precautions

must

be ob-

film:

prescribed

trays,

processing

darkroom

solution

temperatures,

and processing

limits.

tanks,

holders

solutions with

scrupulous

etc.,

without

suitable

that

withstand

contaminating

safeguards

and

the the

lighting

chemical

solutions.

controls

to avoid

cleanliness.

PROCESSING

processing

(Figure

so that

from darkroom to avoid

the

the film

4-6),

film

bending,

the processing

is suspended

holder

conditions

in a processing

and is designed

visible.

Each

affects

must

film.

Maintain

enough

removed

in turn

film

since

concentrations,

equipment,

action

TANK

useless.

results,

chemical

fogging d.

becomes

important

radiographic

Maintain

b.

the

PRECAUTIONS

in processing

times

are

it and

consistently

a.

radiation

radiograph

PROCESSING

served

has

a radiograph

worthwhile

To obtain

placed

grains

as short

exposure

in making

2.

corners

contrast,

large

need

PROCESSING

otherwise

under

Film

characteristics,

as to film

image

volved

deep

good

can be tolerated

of various

a radiographic

latent

V

have

on the

GENERAL

Once

upon

is based

quality.

exposures

that

recommendations FILM

radiographer

fast

to make

by the

405

by the

and

and

advantageous

FACTORS

used

to avoid wrinkling,

holder

to fit the

that

dimensions

vertically.

during film

solutions

holds

Prior

exposure. fog. the

of the

This

The

or crimping film

and

wash

water

are

to processing removal

the

film

is grasped

by its

handling.

The

firmly

by each tanks.

of its Once

film

is

is accomplished

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edges

film

or

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4-9

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for

WATER INLET _

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processing.

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The

advantages

of tank

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are: a.

The

b.

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solutions

readily control

reach

all

of the

water

immersed

controls

the

C.

Easy

film

handling

is permitted

d.

Time

and

space

TANK are

washing,

PROCESSING five

and a.

are

of both

in which

temperature

the

of the during

sides

of the

processing

film. tanks

are

solutions.

processing.

saved.

PROCEDURES

separate

steps

in proper

tank

processing

developing,

stop

bath,

fixing,

drying.

Developing.

Developing

particles This

in the process

amount

and

strength

film

the

when

bromide

limits processed.

in industrial

in the

film

To

obtain the

film

is is

solution.

the

is and

consistent

In practical is

of the

applications with

to the

the

the

the

contrast

a solution

chemical

created

of time

to the

the

solution is kept

by

the

and temperature

The

chemical

image length

temperature

determined the

solution.

and that

bromide

silver.

developer

proportional

is

silver

metallic

radiographic

proportional inversely

to

of time

Assuming

time

obtained

in the

a function

results,

development

of reducing

emulsion

placed

density

process

and

process

of the

of the

solution,

radiographs

chemical

changed

constant,

developing

temperature. narrow

commences

temperature

remains

the

portion

remains

through

is

exposed

of silver

strength

being

portions

type density

within film desired

of 68°F

V 4-10

(20° C),

and

a development

(i) Manufacturers

whenever

To avoid

limits.

than

the

ment

so that

areas

the

film

solutions

film

hanger

flow

vertically

and

in the

charts

developing

solution

is checked

beyond

before

of the tending or

thus

For

this

When

to rid

developing

retarding placed

emulsion

and

the

Warm solucan soften

uniform

from

film

of develop-

solution

tank

bubbles.

the

chemical gravity

development

in the

of air

moved

and

of the specific

to obtain

is completed,

horizontally,

com-

(insufficient

off.

reason,

first

the

development

recommended

chemical reaction. to fog the image,

sloughs

are

procedures.

in underdevelopment

downward,

pass.

is agitated.

until

minutes.

process, the waste products of the film, having a higher

is tapped

thereafter,

eight

time-temperature

result

it wrinkles

they

and

as to proper left

due to retardation overdevelopment,

solution,

the film

and

exists

is never

the development at the surface

reaction

five

temperature

cold

emulsion

(2) During

film

Solution

since

film density) tions cause the

doubt

fogging,

mences,

between

recommendations

consulted time

time

the

Each

is

minute

shaken

side

to side

for

solution

grows

a few

seconds.

(3) In use, weaker

the

because

the

silver

The

rate

grains

of this of the

rate

films

activity

the

solution.

by cutting

the

volume

strips

activity,

used

does

it is good

density into

of the

solution

are

of work

by processing

film

and

practice

the same

more

to test

by

of the

One

to X-rays

frequent

are

films. testing

day before

obtained

each

strip

strip

is then

standard,

test

solution

obtained with and developed

exposure,

as the

each

determined

results

wedge.

activity

and

is replenished.

densities manner,

after of the

number

exposed

comparison

processed

require

solution

with

products.

to the

a film

strips

steps

as solution

not

in reaction

ability)

the

progressively

reaction

intervals,

(development standards,

Similar of all

in fresh

maining

At periodic

activity

acceptable

standard

exposures

chemicals of waste

is proportional

wedge, and comparing film exposed in the

in a fresh

developed

active

buildup

depletion

is tested

through a stepped those of a standard

of the

developed.

If below

(4) Developer

of developer and the

chemical

of depletion,

is tested.

tainlng

strength

of expenditure

bromide

density the

chemical

and When

con-

the

re-

the

of developer

commencing

film

processing.

(5) Developers The

are

solution

developer, powder,

commercially

is formed though

more

and is normally

available

by combining expensive, used.

in both the

powder

developer

is much In preparing

easier

with

and

liquid

water.

to prepare

or replenishing

form. Liquid

than developer 4-11

solution,

the

manufacturer's

directions

are

followed

in detail.

V b,

Stop Bath. When film of the solution remains continue

until

acid

water,

and

film,

and

the

solution serves

prevents

residual

development

and

alkaline remnants to function in the

bath,

a solution

developer

film

of acetic

solution

streaking.

of the developer, desired manner.

from

The

stop

permitting

the

bath the

acid

stop

bath

which

is maintained

solution.

The

seconds,

and

stop

is available,

bath

bath

acid

is used,

each

gallon

mixing

acid; the

acid

(never

the bath

becomes

quality

and when changes

to a blue the

solution

treat

the

equivalent

after

completion

of the

darken

mildly

acid

unexposed hardens placed solution

upon solution,

portions the

emulsion

in the

fixer

of the solution,

still

going

silver the on.

which

silver

exposure of the

film

gelatin solution, bromide. film The

and and

clears, total

bath

solution

in

of a to water

to avoid

is yellow When

under

in color

the

color

safelight

of stop

remaining

stop

bath

and

bath

illumina-

will normally

affecting warm becomes

In time, but the

emulsion

is not removed

silver the

air

dependent for

Fixer,

bromide

exposed drying.

clouded

dissolution

required

film

the radiograph. the

without

in the

processes,

ruin

permitting

time

be followed

slowly

clear.

dark

removes

the film

to

14" by 17" films.

to light,

dissolves

of acid

and is replaced

gallons

bromide,

developer

glacial

constantly.

appears Five

of one hundred

unexposed

is added

is almost

is replaced.

ounces must

or

is mixed When

and preparation

use

stop

safelight,

purple,

If the

it will

repeated

in the

acid

which

of solution.

directions acid

in uncontami-

28% acetic

the former

stirring

A fresh

under

tion,

Fixing.

after

radiographs.

viewed

while

If no

to placing

four-and-one-half

acetic

acid)

spent

is rinsed

in the handling

Glacial

to the

30 to 60

solution.

prior

gallon

Manufacturers

as the

for

fixer

available from

are

particularly

solution. water

development

to each

proportions

bath,

to the

two minutes

commonly

of acid

of solution.

stop

after

temperature

in the bath

transfer

commercially

most

same

is agitated

at least

from

16 ounces

glacial

poor

for

at the

for

film

water

acetic water,

film

removed

is mixed

with

(3) Stop

then

running solution.

glacial

4-12

this

stop

the

(2) Stop

are

The

a quantity action will

development is complete the film is removed from the developer allowed to drain for a second or two. The film is then doused in

nated fixer

fixer

to remove

developing solution, and the developing

and

developer

C.

from the emulsion,

is removed.

uneven

also neutralizes the in the fixer solution

(i) After

is removed within the

from

portion. When

upon

the

fixing

is twice

It also

first

as a result

of the

strength

and hardening

a the

dis-

of the

processes the

amount

of

time L

. 5

necessary

Longer swelling

time,

of the

times, (1)

to clear

fixing and

loss

solution

of the

developer

improper

hardening,

overly

and

salts.

solution limit

first

to the

the

and

dilution by the

solution

There

the

acidity

solution

for

film

and

of fixer

as evidenced

It is directly

is agitated.

by the

and

stop

bath

after

some

of the

however,

a

two or three

replaced.

by the

proportional

or

of dissolved

is,

solution

care

to wrinkle

by removing

fixer.

as that

at two minute

film

accumulation

be replenished

is discarded

range

Particular

emulsion

and the

of replenishment,

and replacement

of the

through

may

of replenishment fixation.

15 minutes. drying

same

the

solution,

it with undiluted

effectiveness

replenishments

in the

films,

solution

replacing

long

70 ° F.

cause

is completed,

depleted

on the

in the

65 ° and

which

fixing

becomes The

between

placed

until

carried

and

at a temperature bath,

temperatures

When

than

abnormal

densities.

stop

high

off.

silver

film

is maintained

thereafter solution

more

emulsion,

intervals

water

not exceed

can cause

or slough

rinse

It should

solution,

to avoid

Fixer

film.

of a weak

of lesser

Fixer is taken

(2)

film

the

indicative

The

frequency

is determined

length

of time

to the

by

required

number

of films

processed. (3)

Fixers

are

commercially

available

in both

powder

and liquid

form

and

the fixer solution is formed by combining the fixer with water. Liquid fixer is easier to handle and is most commonly used. In preparing or replenishing fixer followed in detail. d.

Washing. fixer from water films and

After fixing, the emulsion.

so that

changing

water.

going

through

the tank. film

moved

emulsion wash

the

flow

Each When

each

The

is first

film

receives

(1)

Temperature.

fresh The

can

cause

tures

in the

the

processing

four

drain

end

to be

constantly the

processes

times

equal

through

of the

number

without

eight

of time

procedure

with

to handle

and

proceeding

are

process to remove the immersed in running

enough

a period

are

This

tank,

and

insures

that

water

in the

crowding,

the

volume

to twice

the

of

the

fixing

processing then

the

of

cycle,

progressively

last

wash

any

water.

temperature

important factor of the with a water temperature tures

for

in the

intake.

is with

directions

is in contact

and fixing

is between

of films

placed

the

is large

developing

is washed

a number

toward

manufacturer's

surface

tank

of water

film

the

films undergo a washing The film is thoroughly

all of the

the hourly

time.

solution,

of the

wash efficiency. Best results between 65 ° and 70F since

same

damaging solutions.

effects

as those

At low temperatures

wash

tank

is an

are obtained higher temperaof high very

temperalittle

m

m

r

4-13

washing

action

takes

place.

V (2) Wetting.

When

water

cling

to the

cause

water

marks

sibility

of water

is removed

emulsion.

from on the

damage,

finished

film

the

final

small

cabinet

where

air

manual 5.

step

Automatic

film

chemicals,

of film

processing

To lessen

drying. Wetting cause the water

necessary

processing is made

is drying,

heated

air.

406

When

4-7

usually

agents, to drain

accomplished

are designed of the film.

by hanging

is a graphic

a processing

used

to If no

in a position

representation

unloading

in less

system

wherever

the

all required

same

the

than

for

of the

high

maintained

and

of much

This

continual

operated,

speed

agitation

of the

film those

steps

entire processing

and drying than

them

only manual

the

high

automatic

quality

film, makes

the processing

processing,

temperatures;

higher

around of work

and the

Though

tank

15 minutes.

chemicals;

at relatively

built

volume

processing film.

as those

of special

radiographs

film;

with

jets

processing

of units

processed

FACILITIES

facilities

processing activity.

are type

consist

accomplished,

The

and

may

location, of work

to facilitate

the

of a single and

to be done. logical

must

with

safelight

of an intensity

film

by exposure

be satisfied

to light;

room

or of a series

size,

requirements

4-14

and

GENERAL

Darkroom

signed

the

use

properly

produce

are

and

are

by the

DARKROOM

1.

unit

of all solutions

consistently manually.

be air-drled

Figure

accomplish

is completed

possible

maintenance

may

are

They

is loading

cycle

pos-

cycle.

machines

machines

in an automatic

the agent

PROCESSING

processing The

operation

ume

FILM

film

freely.

processing

and mechanics.

economical. used

circulates

AUTOMATIC

will

film.

is available

film

of

drops

in a wetting

by hanging the film in a drying cabinet. Drying cabinets permit flow of heated and filtered air to reach both sides drying

drops

these

film.

is immersed

evenly

The

tank,

to remain

for one or two minutes before available aerosol solutions,

from

wash

If permitted

or streaks mark

the

then drained commercially

Drying.

e.

film

design The

flow

of rooms

of the location

of film

sufficient

for

processing

the

steps

each

for

dependent within

processing

of a darkroom; operations against

of film

designed

are

of equipment

through

be protected

all

facilities

in the construction

and it must

where

light

handling a specific

upon

the

volis de-

Two

it must without

the

facility

cycle.

from

and

be lighted endangering

outside

sources.

FIXING

FILM ACIDIC.

SILVER

SALTS

EMULSION.

SUSPENDED

PROTECTIVE

68"

CONTINUES DISSOLVES

IN AN

NEUTRALIZATION. UNEXPOSED SILVER

ALLOWING

GELATIN

COATING.

THEM

TO FALL

HARDENS

(TANS)

5 TO 15

MINUTES.

TWICE

THE

CLEARING

WASHING

CLEAN THE SILVER SALTS ARE ACTED BY RADIATION. THE INTENSITY REACTION

IN THE

UPON OF

EMULSION

PROPORTIONAL

AMOUNT

FILM.

FILM.

L

EXPOSURE

DIRECTLY

SALTS

TIME.

1 THE

FROM

OF RADIATION

IS

RUNNING

4 TO 8 TIMES

REMOVES

CHEMICALS.

ALL

68"

WATER.

HOURLY FLOW TANK VOLUME.

TO THE 10 TO .30 MINUTES.

RECEIVED.

TWICE

FIXING

TIME.

l WETTING

DEVELOPER

ALKALINE.

AEROSOL

68"

CHANGES

THE

TO BLACK

EXPOSED

METALLIC

SILVER

ELIMINATES STREAKS.

SALTS

SILVER.

0.5

5 TO 8 MINUTES.

SOLUTION. MOST

WATER

SPOTS

AND

TO 1 MINUTE.

1 STOP

DRYING

BATH

ACIDIC.

68 °

NEUTRALIZES STOPS

THE

THE

DEVELOPER

DEVELOPING

WARM, DRIES

AND

FILTERED, THE FILM.

CIRCULATING

AIR

PROCESS. .:30 TO 45

MINUTES.

1 TO 2 MINUTES.

Figure

4-7.

Manual

Film

Processing

4-15

2.

SAFELIGHTS

The

placement

protection bench);

against

but

in the

in the

less

installations

safelights protected

of film

by opaque

to the

during

material

difference

unexposed

film

in the

developing

and

light

during

only

under film

the

the

is handled fixing

for (the

areas;

time

by test. and

handling.

exposure;

exposed

distance A portion

after

and

The

standard

protected

loading

and normal properly areas.

simplest

test

for

conditions

equiva-

of the

film

test

processing,

portions

V

maximum

Safelights of correct wattage, film, can be used in all of these

as safe

normal

between

by the need

where

be determined

encountered

is no density

areas

is determined

and drying areas. distance from the

can

is exposure

to those

darkroom

protection

(white) in washing and at the correct

Safelight

light

light

adequate

safelight filtered

lent

of safelights

of the

is

if there film,

the

is safe.

3.

PROTECTION

Protection

AGAINST

of darkroom

a matter

of proper

light lock Light-tight

OUTSIDE

spaces

against

safeguarding

made with ventilators

LIGHT outside

through

light

the use

penetrating

of a door

double or revolving doors; are used to prevent light

through

locked

or a labryinth entry through

entrances

from

the

is

inside;

a

(maze) entrance. the darkroom ventilat-

ing system. 4.

WALLS,

The

walls

pleasing

CEILING

and

ceiling

light

of the

color

that

areas

where

chemicals

room

floors

are

proof

material.

5.

chine, room end

handling

1.

all

of unexposed

Usually

the and

usually

painted

amount

with

semi-gloss

of safelight.

protected

with

The

ceramic

a chemical-resistant,

tile

paint walls

of a

in the

or glass.

waterproof

and

Darkslip-

DARKROOM

Since

a darkroom

DARKROOM

are

with

equipment

machine.

conditions. is within

407

is used, film

machine the

darkroom

facilities

of the processing and

film

not yet

is installed

remainder

takes

designed

within

processed,

through

in an open

are

place a wall

the

to ma-

requires so that

the

darkloading

area.

EQUIPMENT

GENERAL

The

loading

are

standard

ing of film loading 4-16

the

splatter

covered

processing the

only

may

are

a maximum

PROCESSING

automatic

accommodate

darkroom

reflects

usually

AUTOMATIC

When

AND FLOOR

bench,

film

darkroom holders

bench.

cabinets

equipment.

and The

storage loading

storage

and bins,

Handling of processing

facilities

for

processing

of unprocessed hangers

holders

are

tanks, film,

all

and hangers,

and film

loading

accomplished and

light-tight

and

driers unload-

at the film

V

storage k..j

bins

activities

are

of film

distance

from,

separated 2.

the

processing

are

located

tanks

twice

3.

408

CLEANLINESS

for

and

holders,

of the

should

wash

tanks

have

drying

care,

be handled

other

radiographer.

k.i

all

to,

areas

but

of the

"dry" at some

darkroom

are

to film.

fixing,

tanks

the

four

aligned

amount times

tanks

and washing

are

of work

that

can handle

should

be the

times

as large.

processes

in the

order

of

can be done.

approximately

same

size,

fixer

must

be kept

during white

in clean

to store clean

the

film

racks,

step,

entire

the

exhaust drier

and

static static

radiographic

used

in processing

during

fan,

may

and

be conven-

Images

chemicals preferably electricity electricity,

and clean, of the

of dirt,

and area

and

to hold

static

should

lead

ruin

and

chips, film

result

a radiograph.

access limited to can result in the area

down

marks

of

film,

on the

streaks

in a separate damp

holders,

and nicks

stains

immaculately contamination

Film

and unloading

Film

scratches

chemical

process.

loading

hangers.

surroundings. crimps,

Similarly,

encourage

intake,

processing

gloves

handling

in preventing which

air

last

handling.

only

screens,

so it is advisable

assists fabrics,

bath

a filtered

of film

radiograph.

Floors

humidity

bath,

fixes

at least

is the

and

mounting

or nicked

of film,

in which

accessible "wet"

The

development

The film processing area must be kept those who work in the area. Chemical used.

area,

damage

stop

tanks

stop

importance

with

and

in a worthless

ruin

and

darkroom.

and

in film

is of great

scratched

"dry"

or chemical

at normal

should

ease

be handled

screens

This

be readily

developing,

of the

sizes

Since

located

film

in the

tank

cabinets

iently

should

The

area.

CABINETS

element.

Cleanliness

tanks.

Developer

as large,

drying

a heating

should

water

area

relative

hour.

DRYING

Film

used

"wet"

developer

per

place,

inadvertent

tanks The

40 films

take

bench

TANKS

in the

A five-gallon

loading

processing

PROCESSING

The

in the

handling

to prevent

processing.

C

located

until dust.

on film.

be avoided

by the

they

are

High Nylon

and

2. _

V

_

CHAPTER TABLE

Par

5:

OF

SAFETY

CONTENTS

Page

agr aph

500

GENERAL

501

UNITS

502

MAXIMUM 1.

.......................................

OF RADIATION PERMISSIBLE

General

DOSE

...............

5-3

.........................

5-4 5-4

Concept ................................ AGAINST RADIATION

1.

General

2.

Allowable

3.

Working

4.

Shielding

5-5 5-5

.....................

...................................... Working

Time

Distance

5-5 ..........................

5-6

...............................

5-8

.....................................

5-9

5. Gamma Ray Requirements .......................... USAEC RULES AND REGULATIONS ......................

5O4

°

m

General

2.

Exposure

of Individuals

3. 4.

Exposure Permissible

of Minors Levels

5.

Personnel

6.

Caution

7.

Radiographic

8.

Radiation

9.

Radiation

Signs,

to Radiation

Exposure

Devices

.....

Areas

Storage

......

5-18

Containers

Requirements

......

5-19 5-19

2.

Pocket

3.

Film

4. 5.

Survey Meters ................................. Ionization Chamber Instruments

6.

Geiger

7.

Area

INSTRUMENTS

. .................................... Dosimeters

Alarm

and

Pocket

Chambers

................

Systems

Figure

5- 2

Figure

5-3

Occupational

Figure

5-4

Current

Figure

5-5

Figure

5-6

Radiation Symbol Pocket Dosimeter

5-22 5-22 5-23

.....................

External

5- 24

.............................

5- 24

..............................

Concept ................................ Protection Constructions Occupational

Radiation External

5-20 5-20

................................

SAFETY

. . .

5- 20

...................................

Banking Radiation

5-18

...........

AND MEASUREMENT

General

Counters

5-15 5-15

...............................

DETECTION

Badges

5-14

...................

and

Instrumentation

Surveys

Areas

5-18

and Signals

1.

5-1

in Restricted

.............................

Labels,

Survey

5-14

.............................. of Radiation in Unrestricted

Monitoring

ELECTRICAL

506

5-12 5-14

......................................

RADIATION

505

Figure

MEASUREMENT

......................................

2. Banking PROTECTION

503

5-3

DOSE

5-24

Exposure Radiation

............ ...............................

5-5 5-13

.................... History... Exposure

•...................

....... .........

5-16 5-17 5-19 5-21

TABLE

OF

CONTENTS

(CONT)

Paragraph

Page

Figure 5-7 Figure 5-8

Pocket Film

Badge

Table 5-1 Table 5-2 Table 5-3 Table 5-4 Table 5-5 Table 5-6 Table 5-7

RBE

Values

5-2

Changer

and

Charger

........................

5-22

....................................

5-23

...................................

5-4

Radioisotope

Dose

Rates

...........................

5-6

Radioisotope

Dose

Rates

vs Distance

Approximate

X-ray

Approximate

Gamma

Half Ray

Value Half

Exposure

Limits

in Restricted

Exposure

Limits

in Unrestricted

..................

Layers and

.................

Tenth

Areas Areas

5-9

Value

5-10 Layers

.................. ................

......

5-10 5-14 5-15

V

CHAPTER

5OO

SAFETY

GENERAL

This

chapter

protection

is designed devices,

regulations

nor

cautioned effects radiation

cannot

be detected

immediately adequate

The

enforces

Interstate Coast

active

Guard

material.

limit

exposure

government certain

emphasis

safety

of the

USAEC

with,

all

practices

or who

the Civil

regulations have

levels,

on safety in all

handling

covering

and

Most

safety

upon

detection

Energy

Commission

and

of radioisotopes.

use

and

covering

regulations

protection the

The

Since effects

Board,

must

have

knowledge

is safe,

but

it is only

the United

use,

the

handling,

designed

to

general

mandatory'

radiographer

do

of radioare

for

is of the

damaging

regulations

indicates

by a licensee

its

transportation

areas.

radiographer

Radiation

the

to afford

practices

The

is dependent

Atomic

All of these

radiation

is employed

and

Aeronautics

similar

of government

of radiation.

senses,

States

procedures,

regulations.

predictable.

protection

material.

to safe

and

human

the

states

safety

guide.

safety

characteristics

covering

safety

various

known the

United

Commission,

safety

effective

personal The

of radioactive

radiation

This

of the

regulations

enforce The

and transportation

by any

apparent,

safety

are and

shielding.

Commerce

States

body

latest

effects,

radiographic

It is not an interpretation

as a complete

of the

human

on these

of the basic

equipment.

aware

on the

based

devices (USAEC)

detection

himself

not become and

some

is it to be considered

of radiation are

to present

and

to keep

practices

and

5:

public.

nature who of,

of sure

is a licensee

and

comply

j

working 501

pertinent with

UNITS

regulations.

it permit

Radiography

OF RADIATION

is of primary

as those

it to be. DOSE

For radiation safety purposes, exposure

as safe

MEASUREMENT

the cumulative effect upon the human

concern.

Since the damaging

body of radiation

effects of radiation to living cells

are dependent upon both the type and the energy of the radiation to which they are exposed, it is impractical only to measure exposure

is first measured

radiation quantitatively. For this reason,

in physical terms; then, a factor allowing for the relative

biological effectiveness of different types and energies of radiation is applied. i.

The units used to measure a.

Roentgen.

radiation exposure are defined as follows:

The roentgen (r) is the unit measure

of X- or gamma

radiation

in air. It is defined as the quantity of radiation that will produce one electrostatic unit (esu) of charge in one cubic centimeter of air at standard pressure and temperature.

One roentgen of radiation represents the ab-

sorption by ionization of approximately

83 ergs of radiation energy per gram

of air. In practical application, the milliroentgen (mr), one thousandth of a roentgen, is often used. The roentgen is a physical measurement of X- and gamma

radiation quantity.

k_i 5-3

Rem.

b,

The

roentgen

equivalent

man)

on man. biological Rad.

Co

do

is a measurement

is the

unit

It represents effectiveness

The

tad

absorption

of energy

per

absorbed

only

Rbe,

value

assigned

effect

on the human

The

effectiveness}.

to X-

gamma

to various

Practically,

is the

the

rays;

unit

(relative

in rem

is the

product

RBE

Radiation

of rem

dose

dose

safety of X-

is equivalent

to the

one.

A measurement

502

MAXIMUM

1.

1

BETA PARTICLES

1

THERMAL

5

tad

NEUTRONS

FAST NEUTRONS

10

ALPHA PARTICLES

20

established

radiation dose,

of roentgen

PERMISSIBLE

and dose

by the

biological of the

Committee

tad

and

on

in terms

is simplified (2) the thus

of rem

dose.

by two facts,

rbe

of both

becomes

The

calcuIating

(1) the

roentgen

X- and gamma

a measurement

radiation

of rein

is

dose.

DOSE

GENERAL

It is impossible posure as,

GAMMA RAY

and gamma

type

RBE 1

are

to any

Values

X-RAY

levels

The

determined

rbe National

of

of 100 ergs

applies

of radiation,

RADIATION

2.

rad

V

relative

of exposure.

is called

dose

5-1.

by the

of measurement place

the

rbe. Rbe values have been calculated by the Radiation Protection as shown in Table 5-1. Table

of radiation

multiplied

at the

types

body,

{roentgen

effect

an absorption

material,

and

the rem

biological

It represents

of irradiated

roentgen applies of radiation.

radiatton's

only and

the

dose)

by humans.

gram

in air

to define

the absorbed dose in fads of the radiation absorbed.

(radiation

radiation

used

and impractical

to radiation.

"...the

dose

to safeguard

Permissible of ionizing

radiation

dose

radiographic

is defined that,

in the

by the light

personnel National of present

from Bureau

some

ex-

of Standards

knowledge,

is not

V 5-4

expected

to cause

lifetime."

appreciable

Maximum

missible Currently

injury

dose

to a person

is the

dose, under prescribed conditions accepted mpd, established through

regulations in any limited

bodily

permissible

on Standards

for

Protection

at any

numerical

value

of exposure, experience,

Against

time

during

of the

his

highest

per-

stated in units of time. is contained in USAEC

Radiation.

Maximum

radiation

dose,

period of one calendar quarter, to an individual in a restricted area, is normally to 1-1/4 rem. Maximum permissible dose per year must not average over 5

rem for tolerance

each year past dose levels.

the age 18. An average weekly dose Under certain circumstances defined

exposures

up to 3 rem

per

calendar

of 100 mrem by cognizant

regulatory

bodies,

Applicable the National

radiation safety publications are issued by the National Committee on Radiation Protection, the USAEC, and

quarter

may

is within government

be permitted.

Bureau of Standards, state authorities.

The radtographer should be cognizant of the information in the "AEC Licensing Guide for Industrial Radiography", which is available from the U.S. Government Printing Office. 2.

BANKING

CONCEPT

The foregoing permdsslble radiation exposure rates are based on the banking concept of radiation exposure.

This concept considers that an individual should not be sub-

Jected to radiation exposure prior to the age of 18. individual is given a credit of 5 rem. 12 rem.

Figure

%,.,

5-1

illustrates

the banking

150

For each year of llfeafter 18 the

_n ,_y one year should not exceed

c¢,ncept.

[ 5 REMS PER YEAR EACH YEAR AFTER

_, o

Exposure

1

DEPOSITED AGE 18.

FOR

50 RADIATION BANK

i

n,, w a.

ACCOUNT

15

25

20

Figure 5-1. 503

PROTECTION

1.

GENERAL

Three

cardinal

AGAINST

principles

35

30 AGE IN YEARS

Banking

40

45

Concept

RADIATION

govern

safety

practices

for

controlling

body

exposure

to 5-5

radiation; graphic 2.

time,

distance,

installations ALLOWABLE

The

amount

and

are

shielding.

designed

WORKING

of radiation

Safe

by applying

absorbed

by measuring

Allowable

by the human

3.

WORKING greater

the

The

inverse

square

a source.

time

distance

intensity

in hr/wk

from

law

body

is directly

proportional

2 mr in one minute minutes. Allowable and

substituting

= permissible exposure

The

inverse

radio-

V

to the

at a given point working time is

in the

following

in

equation.

exposure in mr/wk in mr/hr

rate

and I are methods

5-2

dose

rates

source,

to calculate

square

law

the

radiation (Figure

lower

the

intensities

2-8)

exposure

received.

at various

is expressed

distances

as:

D2

I

where I illustrate

a radiation

is used

I1

lists

and

DISTANCE

The from

radiation

working

techniques

principles.

TIME

time the body is exposed. A person receiving a radiation field would receive 10 mr in five calculated

radiographic these

D

2 1

intensities at D_ and D respectively. used to calculable radiation intensities of commonly

Table

used

5-2.

RADIOI SOTOPE

radioisotopes

Radioisotope

The following examples in terms of dose rate. referred

Dose

14.5

IRIDIUM-192

5.9

CESIUM-1.37

4.2

THULIUM-17O

0.03

examples.

Rates

DOSE RATE R/HR/CURIE EMt SSIV|TY

COBALT-60

to in the

Table

AT 1 FOOT

V 5-6

Example

1:

Given

a 12 curie

Cesium

137 source,

what

is the emission

at 3 feet ? Step 1:

From Table at one foot; foot

Step 2:

Step

Step

3:

4:

I=

5-2, thus,

the, dose the dose

is 12 x 4.2

or 50.4

rate rate

r/hr.

50.4r/hr

D

= 1 foot

D1

= 3 feet

Substituting

in the

I1

12

50.4

32

Solving

for I 1

inverse

square

12 11

Example

2:

=50.4x--=

A 35 curie feet

Step

1:

2:

Step 3:

50.4x..-_-=

32

5.6r/hr

of Iridium

a workman.

192 Is used

What

dose

rate

at distance

will

From

Table

5-1,

the

dose

rate

of Iridium

at one

foot;

thus,

the

dose

rate

of a 35 curie

is 35 x 5.9

I

= 206.5

D

= 1 foot

D1

= 20 feet

Substituting

or 206.5

206.5

192 Is 5.9 source

r/hr.

r/hr

in the

inverse

square

law

equation

-

.51625

202

Solving

for 11 12

I1

he receive

12

11

Step 4:

law equation

1

source

from

foot Step

of Cesium 137 is 4.2 r/hr/c of a 12 curie source at one

= 206.5

x_

= 202

206.5x_

1 400

r/hr

of 20 ? r/hr/c at one

Example 3:

In example

2,

workman Step

1:

Step 2:

at what

distance

be to receive

I

= 206.5

I1

= 3 mr/hr

D

= 1 foot

Substituting

r/hr,

from

the

3 mr/hr

or 206,500

in the

3

only

inverse

source

should

the

?

mr/hr

square

law

equation

12 m

206,500

Step

3.

D

Solving

for

2

ae

Tables from

Example:

D1

= 6_r_,833 as Table are

Given

Step 1:

Step 2:

206,500 3

=

a source,

3-

x 12 = =

5-3,

is the dose

I

= 14.5

D

= 1 foot

D1

= 2 feet

68,833 feet

list

the dose

by application

rate

what

Substituting

262+

which

derived

the dose

I1

Step

1

D1

D1

such

2

of Cobalt

rate

at 2,

4,

5-8

4:

Solve

inverse

60 as 14.5 8,

etc.

r/hr/c

square

distances law.

at one foot,

feet?

r/hr/c

in the

inverse

square

for

law

equation

I1 12

Step

of the

at various

12

Solving

I1

rates

= for

14.5 dose

x 22 rates

1 -

14.5

x

at other

4

-

distances

3.6

r/hr/c in similar

fashion.

Table 5-3. Radioisotope Dose Rates vs Distance DOSE RATE IN REMS PER HOUR PER CURIE

COBALT-60

DISTANCE

CESIUM-137

THULIUM-170

1 FOOT

14.5

5.9

4.2

0.03

2 FEET

3.6

1.5

1.1

0.007

4 FEET

0.9

0.4

0.26

0.002

8 FEET

0.23

0.09

0.07

0.0004

I0 FEET

0.145

O. 059

O. 042

0.00027

b.

All of the same

foregoing for

intensity

then

apply

settings c.

the

and

Lead,

steel,

personnel ped by

iron, exposure.

layers.

The

radiation

half-value

tenth-value

layers.

nine-tenths

of the layers

radtographer

half-value

are,

of any

based

and

layer

the

are

and

energy

layer

in all cases, should

rely The

is that

amount

determined

See

following

used

law

is the at that

5-4

measurement illustrate

to reduce

and

half

of the

measured

which and

be stop-

of half-value

stop

ts often

of shielding

are

cannot

in terms

5-5. actual

will Half-

in stop and

measure-

to determine the

of

point.

vacuum,

radiation will

should sum

as shielding

which

Tables

examples

and kv settings,

square

in a complete

by experiment

on actual

for to

machine

radiation

efficiency

intensity. only

inverse

efficiency

of shielding shielding

the

recalculation.

of X- or gamma shielding

amount

Similarly, of a given

information.

of no scatter,

commonly

ma

at any point

(scatter)

to measure is that

on the

hold

in X-ray

and

secondary

materials

intensity

predetermined

intensity

however,

it is necessary

Any change

Radiation

all of the

shielding.

law.

calculations

A tenth-value

ment.

with

rate

concrete

radiation

or radiation

measurement

intensity.

tenth-value effectiveness

square

radiation;

intensities

distance

as exact.

layer

rate

intensity

it is practical

of a given

The

inverse

dose

Since

shielding,

dose

on gamma

X-radiation

ideal conditions intensities exact.

and

based

a new

radiation

Only under calculated

SHIELDING

the

be accepted primary

4.

calculating

at a known

requires

Intensity never

are

In determining

measure and

examples

principles

X-radiation.

/P

IRIDIUM-192

application

the of

Example

1:

A 200-kvp

X-ray

radiation shielding,

the

acceptable reduce Step

the

Since

1:

1

machine

is directed dose

rate

safe

limit.

dose

rate

and Table

5-4.

will

reduce

room

a concrete room

(I-1VL) reduces 1

or--

22

; three

reduce

the

Approximate

so that

dose

rate

rate

X-ray

Half

HALF-VALUELAYER

primary

room.

Without

is 500 times wall

is required

to a safe

value

dose

by a factor

rate

V

the to

? of

1 1 1 1 by _--2 x -_ x_ or-- 3 ; 2

HVL

dose

the

occupied

adjacent

adjacent

layer

9 HVL

9 HVL will

in the

How thick

1 1 two I-IVL by _-_2x_-

then

be located

an adjacent

in the

one half-value

etc.,

must

toward

i of--_ 2

by a factor

to an aoeeptable Value

safe

1 or 51---2

limit.

Layers

FOR TUBE POTENTIAL

OF

SHIELDING MATERIAL 70 kvp

50 kvp

100 kvp I

I

125 kvp

150k_

200k_

250k_

300 kvp

i

LEAD (m)

0.05

0.18

0.24

0.27

0.3

0.5

0.8

1.5

CONCRETE (t_.)

0.2

0.5

0.7

0.8

0.9

1.0

1.1

1.2

Table

5-5.

Approximate

Gamma

Ray

Half

and

RADIOISOTOPE SHIELDING MATERIAL ININCHES

COBALT-60

1/10

5-10

Tenth

Value

Layers

SOURCE

IRIDIUM-192

CESIUM-137

1/2

1/10

1/2

1/10

1/2

LEAD

1.62

0.49

0,64

0.19

0.84

0.25

STEEL

2.90

0.87

2.0

0.61

2.25

0.68

CONCRETE OR ALUMINUM

8.6

2.6

6.2

1.9

7.1

2.1

V

Step 2:

C

From Table Is one inch. duce

Example

2:

the

5-3 the concrete Thus, 9 inches

dose

must

workman

to reduce

desired

Seven

dose

3:

the

From Table tion is 0.19

a.

Exposure

be housed the

exposure

area.

occupied

spaces,

permit.

If neither

shielding

that

film

is acceptable.

shielded

exposure

circumstance, be taken

When

account.

safety Safe

the

area.

grapher, effective safe

_._

always

three

and

others

outside safety

distance

must

consideration from

the

radiation

Thus,

for Iridium 1.52 inches

rate

rate

but

7 HVL

will

192 radiaof lead

to an acceptable

areas

should

enough

controls

possibility should

should

safe

consist

of a

radiography

must

(time,

shielding remain

rails

must in the

shielded is distance.

the

area

All personnel

under

this must

be

to enclose

to protect the

to the

must

placed

When

the

shielding)

to exposure,

vicinity.

exposure

specimen

and

or ropes

of

and

be accomplished

be placed

in

combination

specimen,

distance,

in relation guard

outside

radiation

any

to bring

the

as conditions

equipment,

practical

house

be located

of excessive

is available,

factors

to also

be as isolated

radiation

marked

a designated

dose

8 HVL will.

dose

large

distances,

Sufficient who

the

a cabinet

It is not

and adequately

radiation

nor

original

times.

exposure

area the

determined,

practiced

be

into

the

encloses area.

the

the

of sufficient thickness for protection. If is not feasible, then the equipment should

machine

exposure

a room

safely

but

cabinet,

To reduce

shielding

or

or 256

practicable,

X-ray

lead

?

therefore

of-_

to reduce

shielded

the

to 3 mr/hr

shielding

lined with lead of such a room

test.

how much

the lead half-value layer Therefore, 8 x 0.19 or

Wherever

under

dose rate for a workman was 516.25 mr/hr. If

172 times. 1 by a factor ofor 128 times, 27 1 2

rate

required

5-4, inch.

in a suitably

specimens

dose

is required

Area.

room completely the construction

rate

rate

it by a factor

provide

shielding value.

dose

location,

is 3/mr/hr; 516.25 be reduced 3

must

reduces

at his

the

HVL reduces

HVL not

remain

200-kvp radiation is required to re-

value.

the

of 516.25

Step

safe

example it was found that the a 35 curie Iridium 192 source

The

Step 2:

to an acceptable

layer for shielding

In a previous 20 feet from is required

Step 1:

rate

half-value of concrete

the

radio-

radiography simplest,

must

is most

be kept

at a

source.

X-ray Tube Shielding. Theoretically, effectively shields, to safe levels,

all

the lead primary

housing radiation

around an X-ray tube except the useful

5-11

beam. the

Co

Practically,

safeness

this

is not always

of an X-ray

tube

is to measure

The

common

Protective

against

Construction.

radiation Shielding

is lead. protective

thickness.

sheets

that pass through the and air ducts passing pletely shielded. practices.

(1)

It is easily

5-2

of lead requiring

be exercised

to assure

be overlapped,

and

all occupied, then all -- must be shielded.

spaces,

building it is not necessary room is on the bottom floor floor

(2)

used.

shielding to the because

radiation

radiation is very thick and heavy. must be provided

of the If the

construction

and

In either above

At voltages

walls. of its

greater

be so great

the energy of of the sur-

about

the

ceiling, similarly need be shielded.

in Figure case,

or below

the the

5-2

apply

partial

wall

than

400 kv,

the

and

thickness

potentials,

concrete

is used

effectiveness

and its

construction

to into

shielding and brick

to fasten

relative

also

scattering

it difficult

higher

if the The

shielding

as to make

At these

exposure

exposure area -- wall, ceiling room is on the top floor of the

shown

protection

penetrating, and (See Table 5-5.) at all times.

penetrating

requirements

are

V

are

of lead the

lead

as shielding Simplicity.

off and

capability

clearly

based

on two factors:

Gamma

the required protective shielding is excessiveiy Gamma radiation cannot be shut off, and protection

of gamma

radiation

on shielding for protection during gamma distance and shielding is usually employed. roped

shielding

below,

or screws

RAY REQUIREMENTS

gamma

The

above,

shielding

escaping

would

leakproof

Pipes, conduits, must be com-

Though lead is the most efficient of the easily available materials, other structural materials such as concrete often

GAMMA

lead

to shield all of the not all of the floor

of a ceiling.

prevents radiation an adjacent area.

good

lead. area

low in terms

nails

shield employed is dependent upon shielding and the use (occupancy)

If the

shielding

expressed

%J

be

to pro-

comparatively

usually

must

area are and floor

partial

and

about

should

used

must

areas.

of partial

radiation

care

illustrates

to assure

radiation

of lead

rounding

methods

are

way

material

lead, must also be covered with through the walls of the shielded

Figure

The thickness the radiation

available

measurements

Particular

Adjacent

most

only

(unwanted)

Radiation

shielding.

5-12

leakage

of primary

of lead

a.

and the

the area tubehead.

in cost.

Special

case,

it. To limit the unwanted radiation, fixed by a cone or diaphragm at the

tect

5.

the

marked

with

makes

it impractical

to rely

radiography; a combination of The radiation danger zone is

conspicuous

signs,

and

only those

V

!

F//AI

h

EAD

® LEAD

WALL ,,,/

\ I

I PIPE OR CONDUIT

.11/_ r111_ rlll_w r11/,J ,1111

1 LEAD

BAFFLES

/ DUCT

L_/r

3

METHODS OF SEALING NAIL OR SCREW HOLES IN LEAD PROTECTION A - LEAD-HEADED NAIL B-LEAD STRIP FOLDED OVER NAIL HEADS

_/_ WAL

2

/ i//. i.,// " ,- ,,,//. "

,'/i/./

WALL

LEAD I///./.

"

PY4 _Y4

",.IF//>Iw,_

\

o

l/ill

"////j_

_///,

DUCT.,/" 1:7/'_' METHODS OF HANDLING PROTECTION AT FLOOR LEVEL WHEN PROTECTION IS NOT NEEDED OVER ENTIRE FLOOR

METHODS OF SHIELDING WHEN PIPES, DUCTS, OR CONDUITS MUST PASS THROUGH WALLS OF AN X-RAY ROOM

Figure

5-2.

Radiation

Protection

Constructions 5-13

persons the

making

danger

by the

zone

source

possible

Do

effects

are

confirmed

The

continuous

1. The

is based of scatter

gamma

intensity

safely

housed, RULES

and AND

in the

of safe the

radiation

are

zone.

The

distance

area

of

as determined

of the

considered

extent

danger

and

the

zone,

the

calculations

measurements.

radiation

from

sources.

labelled,

use,

permitted

on calculations

of radioactive

every

are

In calculating

by intensity

conspicuously

USAEC

radiograph

strength.

countability

504

the

lead

vaults

and/or

measurements the storage

radiosotopes When

are

necessitates

not in use depleted

taken

they

strict

are

stored

uranium

to insure

pig is not permitting

238.

that

the

leakage

acin

After

source

is

radiation.

REGULATIONS

GENERAL previously

storage,

discussed

and

published

use

in the

31.

These

The

following

three

safety

precautions

of radioisotopes Code

of Federal

parts

regulations

of the are

are

is regulated Regulations, Code

are

subject

also

non specific

in nature.

by the USAEC. Title

10, Chapter

published

to change

The

in the

and are

Handling,

regulations

I, parts

AEC

20,

Licensing

presented

for

are 30 and Guide.

familiarization

purposes. 2.

EXPOSURE

OF INDIVIDUALS

TO RADIATION

IN RESTRICTED

AREAS V

Limitations

on individual

Table

dosage

5-6.

are

Exposure

specified

in Table

Limits

5-6.

in Restricted

Areas

REMS PER CALENDAR QUARTER

WHOLE BODY, HEAD AND TRUNK; ACTIVE BLOOD-FORMING ORGANS; LENS OF EYES; OR GONADS

HANDS AND FOREARMS; FEET AND ANKLES

SKIN OF WHOLE BODY

5-14

1-1/4

18-5/4

7-1/2

V

Doses

ao

F

greater

than

during

any

rems;

(2) the

calendar dose

equals

the

individual's AEC-4 Form

Do

AEC-5,

in Figure the 3.

Radiation are

allowed

no individual the limits 4. Under stricted

PERMISSIBLE

dosage limits thus represent

body,

the

form

recorded

must

be permitted

to the

whole

body

when

added

to the

does

not

exceed

at his dose

concerned

Occupational

This

may

in years

occupational

Current

becomes

specified

areas.

dose body,

age

5-3)__and

5-4.

to work under

approved

whole

table

last

has

does

not exceed

5 (N-18}

rems and

recorded

has

signed

Radiation

Exposure,

quarterly

and

(Figure

where

(3) the

the form.

External AEC-4

3

on Form

be completed

on Form

(1)

accumulated

birthday;

been

individual

provided:

is shown

is the

source

of

5-3}.

OF MINORS

damage

not

to the

individual's

information

EXPOSURE

the

to the whole

accumulated

(Figure

in the

quarter

dose

occupational "N"

specified

comparatively in restricted

less areas.

18 years

of age is permitted

in Table

5-6.

LEVELS

OF RADIATION

circumstances, Exposure are based maximum

Table

a limited limits

severe

as an individual

Regulations to receive

of radiation areas

on an individual radiation levels

being continually permitted.

5-7.

Limits

Exposure

are

1 HOUR

7 CONSECUTIVE

1 CALENDAR

DAYS

YEAR

i00

500

exceeding

is permitted

present

MILLIREMS

TIME

Minors specify

that

10% of

AREAS

listed

in Unrestricted

ages. minors

dosages

IN UNRESTRICTED

amount

in unrestricted

to protect

in Table in the

Areas

in unre5-7. area

These and

r(_il

At'C -'4 Form

Approved

Bureau

of

Budget

Expirmt}on

U,S. ATOMIC

ENERGY

Dnte:

No.

38

Jun_

Rt19

30.

19_]

COMMISSION

OCCUPATIONALEXTERNALRADIATION EXPOSUREHISTORY See

[rl#tructJon8

on

file

Back

IDENTIFICATION I

3

N4MT

DATE

(PWIkT---_.AST,

OF BIRTH

FIRST,

(MO'KTH,

ANO

DAY,

MIDDL£)

Y_R)

OCCUPATIONAL

S_ PI_IOUS SLI_-

[Idlq.OTMl[_ffS -LIST

NAME

AND

INVOCYING ADDRESS

C_

RAD4AT)O_

EXPO-

EI4PLOYE'_

i |.

DAT[5

EXPOSUR["-pIIIEVIOU$

2

SOCIAL

5TCURITY

|.

AGE

_

IN

NO

yI[ARS

(H)

HISTORY E_(v_s

OF [MPtOYI4ENT

(FROM--TO)

7, I'[RIOOS

$

OF EX_:_HE

D05[

HrSTORY

WF,IO(.£ _y (gEN)

ULA1TD

tl.

CALL'tA_TION_--PIE"fllII5S_IE

DO'J_

I1,

OCCI_ATIONAL

CLrRTInCAnON AND

WHOU[

I CEgTI_(

COMPLETE

THAT

TO THE

THE

EXPOSURE

BEST OF MY

H STORy

KNOWLEDGE

USTED

AND

1N COLUNNS

$. _. AND

7 IS

EORREC

T

gELIEr

IIOOy

(A}

_UVSSTIN.E

(|)

TOTXL

rc)

mmrssllcE

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--

_.(e_-,I)

.

__

RTM

[M ExPO_

TO

DAEE

(Fl_OId

ITE_I

14)

--

_

.

Figure

5-3.

PLOYET'S

SIG N ATLIRE

DATT

RTM

11

5-16

(X_--TOTAL

.

,.

Occupational

__

NAME

OF LICENSEE

gEM

External

Radiation

Exposure

History

(Typical)

V

U.S.

ATOMIC

ENERGY

Current Occupational YiCC

COMMISSION

External Radiation Exposure

ItlHr_srtionS

o_z

the

Back

IDENTIFICATION I.

NAME

3.

DATE

S.

DOSE

(PRINT--Last.

OF

gIRTH

first,

[Month.

end

day.

middle)

year)

OCCUPATTONAL

at

$.

RECORDED

whole

body;

PERIOD OF (From--to)

ar

FOR hands

(Specify:

Wholl

end forearms,

body_ feet

skln of

and

6,

anklet.)

PERk_ISSIBLE OF

PERIOD

EXPOSURE

DOSE

9.

I0.

GAMMA

2.

SOCIAL

SECURITY

4

AGE

FULL

IN

NO

YEARS

(N)

EXPOSURE

DOSE

AT

COVERED

FOR

THE

BEGINNING

BY THIS

PERIOD

IIETA

II.

SHEET

[ 7

METHOD

[

Pocket

I

DE

MONITC_RING

Chamber--PC.

(r,m)

13

NEUTRON

12,

(e g,

Film

B_dqo--FB;

CalculaHons_Calc

RUNNING CALENDAR

(Pc,,)

TOTAL

TOTAL FOR QUARTER

C

LIFETIME ACCUMULATEDDOSE 14.

PREVIOUS

TOTAL rein

19.

NAME

OF

I IS.

TOTAL

I

ED

ON

DOSE THIS

RECORDSHEETrim

16.

TOTAL

ACCUMULATED

DOSE

17. rein

PERM.

SEN --

II_

ACC,

DOSE

=

I

IS.

PERMISSIBLE

DOSE

rgm

rein

L/CENSEE

Figure 5-4.

Current

Occupational

External

Radiation

Exposure

(Typical)

PERSONNEL

5,

MONITORING

Personnel

al

(1)

monitoring

Individuals dosage

entering

in any

value (2)

of 5% of the Individuals

During

b,

radiographic

wear

film

dosimeters

and

the 6. The

CAUTION radiation

placed

badge

SIGNS, symbol

is shown

in conspicuous

places

radioactive

materials

"Caution,"

or the word

mined

by

Radiation

specific

Special

bearing tags

Material-Do sealed 7.

radiation

Not Handle.

Notify

not fastened

RADIOGRAPHIC

devices.

sources

when a.

provide Protective

they

are

Radiographic sealed

in the

any

exterior

standards

designed

must

to any

are less

exterior

word is deter-

Area,"

be marked

"High of

with

signs

Material(s)."

" must

be attached

to

device. CONTAINERS and

other

personnel

isotope from

ex-

sealed

as follows: than surface

of 50 milliroentgens device.

the

"Danger-Radioactive

cameras to protect

be

Containers

"Radioactive

If Found,

measuring

sign

four

inches

of the per

from

device

hour

be

range,

in which

required

'_Radiation

an exposure

position

of the

On each

phrase,

isotope

in excess

surface

shall its

must

containers

as appropriate.

words the

symbol

wording

AND STORAGE

for

off (shielded}

on all

containers

in,

DEVICES

position

from

and

standards

level

and

phrases,

Authorities

storage

source

the

or contained

devices

no radiation

zero

doses

this

bearing

Area," such

exposure

have

Pocket

beyond

Signs

Other

and the

Civil

shall

from

indicated

is discharged

or used.

bear

symbol

EXPOSURE

regulations

posure

signs housing

to,

and

doses

immediately.

appear.

symbol

radiation

daily

areas,

Radioactivity

the

sources

Specific

5-18

the

assistants chambers.

be processed

stored,

" must

and areas

bearing

5-5.

transported, Area

their

or pocket of measuring

be read

in all exposure

use.

5-6.

SIGNALS

in Figure

" or "Airborne

materials

or labels

AND

"Danger,

sign

Area,

radioactive

are

and

or dosimeter shall

who in excess

areas.

dosimeters

shall

individual

LABELS,

applicable

quarter

in Table

be capable

chamber

of the

receive,

areas

calendar

radiographers

They

If a pocket

film

specified

pocket shall

to 200 milliroentgens.

restricted

in any

high radiation

either

and chambers

recorded.

value

operations,

badges

or may

of 25% of the

entering

dosage

applicable enter

who receive,

in excess

of age

receive,

who

areas

by:

5-6.

18 years

or may

be used

quarter

in Table

under

receive,

must

restricted

calendar

specified

Individuals

(3)

equipment

the shall

at six inches

60 °

I I I

CROSS-HATCHED

AREA-

MAGENTA OR PURPLE

BACKGROUND

-

YELLOW

5-5.

Figure Radiographic

b,

the

sealed

and

all

storage

devices,

shall

hour 8, For that

radiographic

9.

sealed

no radiation from

any

(meters)

exterior

per

that

any

hour

one

through

meter

of four

surface

or for

in excess

inches

of the

from

device,

radiographic

exposure

of 200 milliroentgens

per

surface. REQUIREMENTS that

calibrated

The

meters

one

used

roentgen

be capable

and

per

operable

shall

hour

of measuring

have

can

the

radiation a range

such

be measured.

entire

required

It range.

SURVEYS for

required

No radiographic radiographic A physical

be available.

exterior

sources

level

it is required

radiation

b.

for

a minimum

to any

operations,

regulations a.

position

containers have

Symbol

measuring

INSTRUMENTATION

RADIATION

Specific

storage

meter

milIiroentgens

necessary

devices

SURVEY

instruments

two

is not

source

at one

RADIATION

survey

exposure

Radiation

surveys

operation

survey

shall are

survey

as follows:

be conducted

instrumentation

exposures radiation

are

is available

unless

calibrated

and used

at each

and operable site

where

made. shall

be made

after

each

radiographic

exposure 5-19

during

operation to determine shielded condition.

its

A physical

Cm

505

is in its device

survey

shielded and

shall

DETECTION

be made

condition

storage

sealed

prior

source

has been

to determine

to securing

returned

that the

each

to

sealed

radiographic

ex-

container.

AND MEASUREMENT

INSTRUMENTS

GENERAL

Various are

source posure RADIATION

1.

radiation

that the

techniques,

employed

tection commonly

used

dose into

The

rate,

the

known

POCKET pocket

such as

charges

repel

each

of the

The trode

are

and the

movable

portion

mutually

repellent,

lens

so placed

of the

electrode

charged,

the

a.

that, appears

pro-

in terms

measurement

as pocket

measure

counters.

of logically

such

that

and Geiger

metal

cylinder,

form and

elctrode carrying when as the

dose

These

cylinder

moves

away

scale

indicator

a dosimeter

is placed

in the

cylinder

chamber.

neutralized,

portions

decreases.

the

the

When

becomes

ionization

the

the

rate

instru-

fixed

scale.

in an area

When

the

of radiation,

ions

As the

lens,

dosimeter

are

attracted

positive

charge

the

repellent

force

between

The

movable

portion

moves

the

(from

they

electhe are

scale the

and the

movable

dosimeter

for use.

ionization

takes

place

to the

electrode

on the

electrode

fixed the

and

portion

is properly

is ready

toward

lens.

an ex-

the

since

transparent the

the

SimultaneousIy,

portion

The

electrode and

cylinder,

charge.

through

and the

Negative

cylinder.

the

charge.

the

essential

fiber

scale,

a potential

and

of a electrical

The

quartz

When

from

on the scale

in a gas.

transparent

a negative

size

or similar

metal-coated

electrode

is viewed

the

(1) like

an electroscope. between

be at zero

to the

approximately

section,

a positive

the

device

causes

and a movable

will

ions

ionization

exposure,

instruments

on two principles:

is applied

each

indicator

positive

s-20

the

charge

of the

and

dose

of

CHAMBERS

is a small

(2) radiation

cylinder

of voltage) a positive

5-6)

and

section

gains

are

other;

dosimeter

source

on the

de-

effect most

is calculated

total and

photographic

excitation

instruments

rely

detection

chambers

AND POCKET

is based

of a fixed

electrode

ternal

for

measure

on matter,

meters.

(Figure

Its operation

the the

of radiation

badges;

as ionization

DOSIMETERS

dosimeter

film

and

measure

however,

used that

energy

Chemical

which

measurement

instruments and

survey

pen.

consisting

hazard

chambers,

fountain parts

and

Since instruments

intensity), are

detection the

of radiant

devices.

as methods In radiography,

radiation

pocket

(radiation

2,

materials.

dose

effects

measurement

by radiation.

and

characteristic

as well

two categories:

dosimeters, ments

and

used,

for

in a gas

total fall

are

on certain

duced

on the

in detection

methods

radiation

based

and

movable

fixed

portion

.T

POCKET

V/l

CLIP_

/ L L l_"

COLLECTING

ll

/ / / } / / / / • / / _)wl • • l l J_'ZJ_J_;Z

Figure

in an amount ionization the

portion

are

in doses

from

Dosimeters

that

chambers.

Pocket

dosimeters

the

chamber

scale

zero

exposure,

the

(operating

on the

moves

across

between

the

quantity

the chamber chamber.

of radiation,

the

the

of

displacement

measure

a sensitivity

quantity

of

of radiation.

that

permits

them

to be

reading

(Figure

5-7)

the

same

purpose

They

are

serve rugged.

electrode

and

across

charging

wall

the

device.

center The

called

pocket

as direct

designed

the chamber

is placed

are

reading

on the

condenser

acting

as the

electrode

charger

plates

and

contains

until position.

the

same scale

When

fiber

the

in the principle

always

be read

charger

and

as the

chamber

ionization on the

across

is exposed

determined

and the

causing

moved

same

the

by the

in the

movable

charge

thus

fiber

of a dosimeter) remaining

directly

chamber.

charger

calibrated

the center electrode of ionization. After

electrode

wail,

the

the the

to radiation,

charge between to the degree

is inserted to a position

has

chamber

electrostat

electrode

of radiation must

movable

chamber decreases the wall in direct proportion

chamber

center

the

the a

a calibrated scale, a lens system, a means of varying to the chamber, and a movable fiber. Prior to use,

ionization in the and the chamber

the

more

is charged to the

Since

is a direct

with

direct

by a separate

supply, applied

chamber

not

A charge

wail

power charge

(Typical)

action.

quantity

designed

central

of a condenser.

ionization

electrode

chambers

are

Dosimeter

0 to 200 milliroentgens.

are

but

principle,

by the

of the

dosimeters

scaled

to the

is determined

l_;_-/_'J--LZ_Z-ZJ_1

Pocket

proportional

movable

Pocket

b.

5-6.

ELECTRODE.

used

indicating

To avoid

error,

to charge

the

5-21

INDICATOR

POLYSTYRENE IN SULATOR

POCKET CLIP

CHARGING DIAPHRAGM

/

V

\

/ BAKELITE ELECTRODE (COATED WITH GRAPHITE)

POLYSTYRENE INSULATOR

CHARGING AND MEASURING CAVITY

Figure 5-7. 3. Thc

FILM film

cadium

badge filters,

(Figure

by an individual a period techniques. By use

of control

films.

5-8)

in which

After ceived.

The

Because

SURVEY of the

of time necessary used for radiation

of a small

is inserted

when

of time,

consists in radiation

usually density

special

of the

of a densitometer Through

this

5-22

film film

density

holder

film.

and

the

comparison,

(Typical)

equipped The

with

badge

is removed

and

to the

is compared of the

amount

or

to be

exposed.

developed

is proportional

of the film

thin lead

is designed

is not to be otherwise

an estimate

the badge, and serve

by stand-

radiation

to that

re-

of a set

of radiation

is made. Film badges and as a check on each other.

re-

dosimeters

METERS number

of instruments

for their use, area surveys.

that

would

be required,

dosimeters and pocket Such surveys require

taining andj)resenting an instantaneous instruments are in common use, the counter.

areas,

processed the

film

X-ray

two weeks,

ceived by the individual, who wore each record total radiation received

,i.

and Charger

BADGES:

worn ard

Pocket _lmmber

and the

excessive

amount

chambers cannot be readily an instrument capable of ob-

measurement of radiation ionization chamber instrument

intensity. and the

Two such Geiger

TYPICAL

FILM BADGE

x._M

FRONT FRONT BETA WINDOW (OPEN) CLIP

_

METAL OR PLASTIC

/___

(SERVES

CASE

AS BETA SHIELD)

REAR

____7__

REAR BETA WINDOW (OPEN)

FILM PACK IDENTIFICATION

i

Figure

r

5.

IONIZATION

Ionization

chamber

two electrodes; trodes;

CHAMBER

and

a power

neutral

battery

required

in terms

because

the

tion.

In this

manner,

ber

instruments

In areas

of low

indicate

accurately

radiation

intensity

flow

the

the

radiation, meter.

by the may

meter

to the rate)

of + 15% except sufficient Radiation

made

The

The (dosage

with

flow

meter,

in low

across

of current

current

the

elec-

instru-

from

the

is calibrated in radiographic

caused

radiation

measurements

the

Individual ions the electrode

which

ionization

containing

When

be calibrated

is measured.

ionization intensity

Geiger

supply.

in the chamber. and upon reaching

battery.

is proportional

chamber

is connected

power

is measured

intensity

an accuracy

usually

which the

takes place potential,

from

ions

of current

on the

(Typical)

of an ionization

with

or roentgens.

intensity are

a battery,

in series

a charge

radiation

attain

usually ionization of opposite

to neutralize

of milliroentgens

terms

consist

supply,

by removing

Badge

basically

connected

ment is exposed to radiation, are attracted to the electrode

Film

INSTRUMENTS

instruments

an ammeter

become

5-8.

by the

Ionization intensity

is not generated in areas

radiacham-

areas. to of low

counters.

5-23

6.

GEIGER

COUNTERS

Geiger counters tivity radiation cathode,

and

utilize detecting

the

gas

is multiplied

into

action

of the

electrons

single

ionization

the

quality

7. Area

ALARM

alarm

bers,

radiographer

with

X-ray

equipment.

installed

requires

X-ray

encounter

X-ray

applicable

to both

5-24

counters

calibrated.

gross

is used are

They

contamination

are

of suspected

high

as gas to cause

an

accurate

to

extremely

surveys,

but

of dose rate. In areas of high radiation to block out, and the meter will indicate

of one

are

or more

sensing

alarm

radiation

use-

are

not

intensity, a false zero

intensity,

elements,

meter.

indication

exceeded.

must

comply

Modern facilities little

certain

Whenever

are

is known

of a

chamber

in-

The

is given

Area

alarm

usually

ionization

meter

is preset

(lighted

lamp),

systems

are

so that when

often

cham-

used

an

perin gamma

SAFETY

The

will

they

event

by the

phenomenon

energy

Geiger

ionizing

caused

This

of a millisecond, a lamp.

any

are

event.

of electrical

for

or a visual

levels

1.

tices

light

to which

is fed to a central

ELECTRICAL

nently

or

in areas

is sounded,

missible radiation radiography.

506

measurers a tendency

ionization

pulse

particularly

consist

output

alarm

first

wherein

ionizations

SYSTEMS

systems

whose

audible

secondary

in a fraction

a meter,

of radiation

an environment

The

amplified

For this reason, should be used.

AREA

create

in the

many,

instruments

to be accurate counters have

reading. struments

tube

tube as an ionization chamber in a high sensivoltage difference between the tube anode and

events.

resultant deflect

ful as detection intended Geiger

the

such

produced

The

indication,

+ 15% for

within

many producing

multiplication. audible

a Geiger-Muller device. The

X-ray are

electrical precautions.

equipment

is being and

a.

Do not turn

power

b.

Insure

grounding

c.

Regularly

d.

Avoid

that

check

handling

power

electrical

machines designed

portable

so that

personnel portable

installations, for

instructions

cables

high voltage

or serviced,

setup

cables

use

procedures

however,

operated

on until

power

safe

hazard;

electrical

permanent

with

for when

should

exposure

are

the

power

circuits.

working Perma-

trained

in safe

X-ray

equipment

following

prac-

precautions,

be observed:

is completed.

complied

signs

when

of wear.

with. Replace

when

necessary.

is ON.

V

e.

If power

cables

as rubber f.

Insure electrical

©

If common use

of X-ray

must

gloves,

that

be handled

rubber

condensers

mats, are

with

power

and

insulated

completely

ON,

discharged

use

safety

equipment

high-voltage

sticks.

before

checking

such

any

circuit. sense

precautions

are

observed

there

is little

electrical

hazard

in the

equipment.

5-25

V

CUAPTER

6:

C

SPECIALIZED

TABLE

OF

APPLICATIONS

CONTENTS

Page

Paragraph 600

i |

GENERAL SELECTION

OF EQUIPMENT

602

ACCESSORY

EQUIPMENT

lJ

2.

6-6

.......................................

6-6

Screens

5. 6.

Masking Material ................................. Penetrameters ...................................

6-10 6-10

7.

Shim

Stock

6-13

8.

Film

Holders

9.

Linear

and

Cones

....................

........................................

6-7

.....................................

and

and

Cassettes

Angular

Positioning Identification

6-7 6-7

..........................

Measuring

Devices

Devices ............................... and Orientation Markers

6-13 ..................

...................

6-14 6-14 6-14

13.

Area Shielding Equipment ............................ Densitometer ....................................

6-15 6-15

14.

X-Ray

6-15

15.

Gamma

16.

Dated Decay Curves Film Characteristic

17.

Exposure Ray

Charts

.............................

Exposure

Charts

General

2.

Movement

3.

Source

4.

Source-to-Film

5.

Physical

6.

Film

6-18

............................... Curves ..........................

Radiographic Equivalence Factors EXPOSURE VARIABLES ............................... i.

6-18

.........................

18. 603

6-5

4.

12.

|

............................ ..............................

3.

11.

z

General

6-5

Diaphragms, Collimators, Filters ........................................

10.

i

.........................................

601

6-21 6-21

.....................

6-22 6-22

....................................... Size

Screens Scatter

9.

Kilovoltage, Source

11.

Specimen

Distance

Arrangement

7. 8.

6-25

.....................................

Contrast,

10.

6-24

......................................

6-25

............................

6-26

..............................

Speed,

and Graininess

...................

....................................... Radiation ................................. Milliamperage,

Energy,

Source

Absorption

and Strength,

and

Specimen

6-26 6-27 6-27

Time and

................... Time

Contrast

................ ...............

6-27 6-28 6-28

|

| 6-1

/

TABLE

OF

CONTENTS

(CONT) Page

Paragraph 604

605

EXPOSURE

CALCULATIONS

1.

General

2.

Double

6-28

................................... Film

3. Radiographic RADIOGRAPHIC 1.

General

Exposures

6-40

.........................

Slide Rules APPLICATIONS

6-42

........................ ......................

6-43 6-43

...................................

2.

Related

Factors

..............................

6-44

3.

Radiographic

Applications

4.

Radiographic

Application

on Welded

T-Joints

5.

Radiographic

Application

on Welded

Corner

6.

Radiographic

Application

on Heat

7.

Radiographic

Application

on Single

8.

Radiographic

Application

on Double

9.

Radiographic

Application

on

on Welded

Application

Flat

Plates

Wail Wall

6-45

.......... Zones

Tubing

6-49

.........

Tubing

...........

6-53

Tanks

...........

6-55

11.

Radiographic

Multiple

12.

Radiographic

Application

13.

Radiographic

Panoramic

Application

14.

Radiographic

Application

on Large

15.

Radiographic

Techniques

of Discontinuity

16.

Radiographic

Application

on Brazed/Bonded

Honeycomb

17.

Radiographic

Application

on Semiconductors

...........

SPECIAL TECHNIQUES ............................ 1. General ................................... 2.

Fluoroscopy

3.

Use

4.

6-56

......... Sections

Amplifier

5.

Television

6-57

................ Pipe

Welds

6-59

.........

Location

6.

Xeroradiography

7. 8.

Exposure Transfer

9.

Stereoradiography

10.

Stereoradiography

11.

Double

Exposure

6-70 6-70 6-70

12.

Flash

Radiography

13.

In-Motion

6-71 6-71

..................

6-72 6-72

...........

6-73

.................................. Process ............................ Exposure

............................ (Parallax)

Radiography

6-60 6-68

.....................

.........................

Double

. . .

6-64

.............................

and

6-59

......

...........................

Radiography

6-57

.....

................................

of Fluoroscopy

Image

Application

on Hemispherical

RADIOGRAPHS

6-50

........

Spheres

on Closed

UNSATISFACTORY

6-48

........

Radiographlcal

607

6-47

.......

10.

Combination

6-44

........

Joints

Affected

Closed

606

6-2

6-28

.........................

......................

............................ .........................

6-73 (Parallax)

......

6-74 6-74 6-75 6-75 6-76

TABLE

OF

CONTENTS

(CONT)

r

Page

v

r v

Figure

6-1

Figure

6-2

Diaphragm, Collimator and Filter .....................................

Figure

6-3

Lead

Figure

6-4

Figure

6-5

Masking Standard

Figure

6-6

Use

Figure

6-7

X-ray

Figure

6-8

Gamma

Ray

Exposure

Chart

Figure

6-9

Gamma

Ray

Exposure

Chart

Figure

6-10

Dated

Figure

6-11

X-ray

Exposure

Chart

(Portable

Figure

6-12

X-ray

Exposure

Chart

(Permanently

Figure

6-13

Iridium

Figure

6-14

Film

Characteristic

Curves

(Types

I, II and

HI)

.........

6-32

Figure

6-15

Film

Characteristic

Curves

{Types

A, B and

C)

.........

6-33

Figure

6-16

Iridium

Figure

6-17

Energy

Figure

6-18

Figure

6-19

Steel Specimens ............................... Common ButtweId .............................

6-39 6-45

Figure

6-20

V-Groove

6-45

Figure

6-21

Correct

Figure

6-22

Incorrect

Figure

6-23

Correct

Angle

for

T-Joint

Figure

6-24

Correct

Angle

for

Corner

Joint

and

Correct

Figure

6-25

Correct Placement

Angle for Corner Joint ..................................

but

Incorrect

6-26

Correct

Angle

and

Figure

6-27

Placement {100% Penetration) ...................... Heat Affected Zones of Weldments ..................

6-48 6-48

Figure

6-28

Circumferential

6-50

Figure

6-29

Double Inside

Wall Application with Tube Diameter ...............................

Size

Double Inside

Wall Application with Tube Diameter ...............................

Size

Figure

Figure

6-30

Masking

Technique

with Metallic Penetrameter

of Shim

...................

6-8 6-8

......................... Shot for

6-11

....................... 1" Material

6-11 6-12

...............

Stock ..............................

Exposure

Decay

Chart

Curve

192 Exposure Thickness

Buttweld

...................... {Modified}

6-19 ...............

6-20 6-21

Equipment} Installed

...........

6-29

Equipment)...

6-30

.........................

6-31

Chart

......................

6-34

Ranges

......................

6-35

............................

for

Angle

6-16

............................

192 Decay

Angle

6-14

..........................

Curve

vs.

Cone

T-Joint

for

for

(100% Corner

T-Joint

Joint

Wail

6-31

Sphere

Weldment

Application

Figure

6-32

Closed

Tank

Figure

6-33

Multiple

Figure

6-34

Hemispherical

Figure

6-35

Panoramic

Application,

Large

Figure

6-36

Panoramic

Application,

Similar

Application

Combination Section

Leg

6-46

Penetration) Detail

. .

Placement

6-46 6-47

Detail

Correct

Detail

............... Area

1 1/4

Inch 6-51

Less

Than

1-1/4

Inch 6-52

......................

6-54

......................... Application

6-46

.....

6-47

Application

Figure

......

Penetration)

(100% Standing

Corner

Single

Penetration)

{100% Corner

6-55

...................

6-56

.......................... Pipe

6-57 Weld

Articles

.............

6-58

.............

6-58

6-3

TABLE

OF

CONTENTS

(CONT) Page

Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

6-37 6-38 6-39 6-40 6-41 6-42 6-43 6-44 6-45 6-46 6-47 6-48 6-49 6-50 6-51 6-52

Table 6-1 Table 6-2 Table 6-3 Table 6-4 Table 6-5

Large

6-4

Welds

Angulation Double Edge

and

Application

Member

Vertical Transistor

Tie

Views

Schematic

Diagram

Schematic

of an Image Vidicon

Sample

Xeroradiograph

Fixture

Standard

Penetrameter

6-67

Resistor

and

Capacitor

.......

6-71

..................

Section

6-67 6-70

................

6-72

....................

6-73

.........................

6-74

.......................

............................

6-76

Sizes

6-12

.....................

6-13

...............................

Applications

of Industrial

Radiographic

Equivalence

of Radiographic

Radiation

.................

6-22

Factors

.................

6-22

Variables

on Desired

Radiographs

Radiograph 6-23

....................................

Unsatisfactory

6-66

....................

Amplifier

Radiography Technique

6-64

....................

of a Fluoroscope

X-ray

Parallax

Effect

6-62

6-65

of Diode,

Typical

Levels

......................

of Transistor

Suggested

Quality

6-61

......................... Defects ....................

Holding

Stereoscopic

......................

6-63

Exposure and Divide

Views

6-60

....................

.......................

Application

Semiconductor Suggested

Alignment

Application

Surface

6-59

............................

Flaw

Surface

Single

Quality

Table 6-6

Pipe

.....................

6-68

CHAPTER

600

and

radiograph

adequate of the

without

Most

previous

any that

of the

proven

APPLICATIONS

shop

contained

charts

graphs

2.

Proper

film

radiographic graph

601

film

1. Selection decisions.

2.

Selection

of X-

c.

Selection

of specific

Ideally, most lends

exposure,

stated, Before

until there

the

capabilities

a particular

discussed

by application to the

presents

charts,

information

reasonable

control with

the

in

ability

of

of the

a basic to use

the

for

the

procedures

4 is an essential can

result

exposure

part

of good

in a worthless

radio-

techniques

that

follow

are

processing.

has

ray

is but

following

related

radiographic produce

desired

equipment

selection

adaptations

and,

test

test

for a task results.

it must This

methods first

be

determination

analyzed.

by using

can be used X-ray

nondestructive

equipment

the

is accomplished

equipment.

one of the

thoroughly

of individual

of the

radiography.

been

equipment

consists

method.

X- or gamma

will task

test

as a test

selecting

to numerous

any particular the

The during

radiography

is a best

radiography itself

in Chapter

film

or gamma

radiography

be made

cally,

reason

for

b.

cannot

been

effective

only

EQUIPMENT

of radiography

that

need

be related

and

of them,

radiographs.

radiographer

devise

technique

processed.

Selection

use.

assure

process,

readily

exposure

of the

a.

determined

ment

OF

of equipment

in common

3.

handling

As previously

can

can

chapter

The

radiographic

as described

An ideal

is improperly

SELECTION

that

influence

radiographer

have

Others

contrast,

or more

as constants

This

tasks.

one

quality

be treated

graphs.

techniques

processing

on correct

and

high

requirements

specimens.

practice.

if the

based

can

exposure

to him,

The

in radiography

equipment.

available

of different

four

to produce

of variables

of the

definition, fulfills

application.

requirements

of radiographic

and understanding

and

that

in charts

majority

knowledge radiography

Any technique

of specific

laboratory

the

sharp These

of the variables

constants

and

for

distortion, is controlled.

is a good

these

number

Many

known

variables

other,

meet

large

information

or to the

minimum

exposure

of radiography.

chapters.

of the

have

where

techniques

procedures

1.

_m

will

density

compromising

follow

all

SPECIALIZED

GENERAL

A quality all

6:

for

any radiographic

the

equipment

machines

a variety

Practi-

available.

by knowledgeable for

test.

choice of tasks.

and isotope

cameras

The of film For

equipand

this

overlap

in 6-5

many areas of test. Except in large production installations, or in a test laboratory, it is impractical to have multiple radiographic equipment. Therefore, it is the responsibility of radiographic test and quality assurance personnel to insure that the equipment and techniques selected are capable of performing the required task. 4. Because of its flexibility, ease of operation, and fewer radiation hazards, X-radiography is preferred to gamma radiography. Gamma radiography is usually selected for industrial applications that involve:

5.

a.

High radiation energy requirements.

b.

I ow testing rates.

c.

Simultaneous exposure of many specimens.

d.

Confined areas where X-ray cannot be used.

e.

Field inspections in areas where electrical power is difficult to obtain.

f.

Tasks where time is not a consideration.

Prior

rapher for

must

the test,

siderations tion 602 1.

to the

among

selection

consider and

of specific

all aspects

the number

influencing available

of the

job.

or frequency

equipment equipment

ACCESSORY

radiographic Available

of similar

selection. is the

equipment

Since

responsibility

for

equipment, specimen

each

task

of the

a test, the

tests

are

the

time

allocated

major

is different,

radiogcon-

the selec-

radiographer.

EQUIPMENT

GENERAL

To create

a radiograph,

To create

a useful

equipment,

the

only

radiograph

working

a.

Diaphragms,

b.

Filters.

c.

Screens

d.

Masking

e.

Penetrameters.

f.

Shim

g.

Step wedges.

h.

Film

i.

Linear

tools

a radiation of quality,

source, additional

of a radiographer,

collimators

and

cones.

material.

stock.

holders and

and angular

cassettes. measuring

devices.

a specimen, equipment includes.

and

film

is required.

are

needed. This

IW"

j.

Positioning

k.

Identification

1.

Shielding

m.

Densitometer.

n.

X-ray

o.

Gamma

p.

Dated

q.

Film

r.

Table

2.

devices. and

exposure ray

exposure

decay

characteristic

(H & D) curves.

of radiographic

and

equipment,

limit

the

of radiation.

by limiting

FILTERS

Filters

are placed

sheets in the

(See

the beam

are

Figure

diaphragms size area.

atomic

X-ray

beam

CONES

thicknesses

to contain

to the

of high

factors.

AND

cones

or built

have built-in adjustable covers a standard film 3.

equivalence

COLLIMATORS,

of X-ray area

charts.

curves.

head

lead,

charts.

collimators,

radiation

markers.

material.

DIAPHRAGMS,

Diaphragms,

orientation

a gamma

6-1.)

specimen

designed

so that

number

useful

and

they

eliminate

metal,

in radiography a°

The

of specimens

material the

available;

however,

(See

4.

action

at a fixed

brass,

copper,

interpreted

of lead

by soft

radiation.

adjacent

of the

thick

specimen,

required.

filters

as specimen

6-2.)

of scatter

X-ray

beam

to

machines distance

steel,

or

By absorbing

the

two purposes: they reduce subject thicknesses to be recorded with one exand

steel,

since

Filters thin

and its

No tables

in radiographing

in the use

designed

amount

Many

Figure

tube-

good

defects

are

particularly

sections. range

of filter results

of thicknesses thicknesses have

thickness; Particular in the

filter

been

are obtained

or copper care must may

be

be mis-

defects.

SCREENS

When the

filter

and

the

area. the

to the

source,

lead filters, 3% of the maximum specimen 20% of the maximum specimen thickness.

exercised takenly

with

and thickness

determine by using filters,

caused

fitted

decrease

usually

at the tubehead.

scatter

ray

They

desired

"soft" radiation of the beam, filters;accomplish contrast permitting a wide range of specimen posure;

of lead,

an X-

radiation

or gamma energy

ray available

beam

comes

is absorbed

in contact by the

with film

film,

less

in producing

than

one percent

an image

through

of

_FOCAL

SPOT

ANODES'/ ! !

\ \

! / !

CONE OR COLLIMATOR

\

I

RADIATION

\

! !

SOURCE

\ \

!

\

/

\

/

\

! I

\ \

/

\

/

\

!

\

/

\

/

\

SPECIMEN

/ / I

& HOLDER

CROSS SECTION

Figure photographic film,

effect.

two types ao

6-1.

To convert

of radiographic

Fluorescent material,

Screens. usually

Diaphragm,

Collimator

the unused screens

are

energy

into

used:

Fluorescent calcium

/

/

can lead.

of powdered

to a plastic FOCAL SPOT

'_

',,, / ..- .,1

FILM AND FILM HOLDER

6-2.

Filter

be absorbed

fluorescent

or cardboard

\

_---v,,- / __/,(///_,r-

Figure

that and

\

\ FILTER j

a form

consist

bonded

AN ODE?_

/

Cone

fluorescent

screens

tungstate,

and

DIAPHRAGM

base.

by

When activated by radiation, the fluorescent material emits light in proportion to the amount of radiation available for absorption. The screens are used in pairs with the film placed betweenthem in a clamp type film holder. During exposure, the photographic effect on the film is the additive result of the radiation, and the light emitted by the screens, impinging on the film. Since the emitted light is diffused, image definition is less sharp when the screens are used. Close contact betweenthe screens and the film must be maintained or the diffused light will cause a blurred, worthless, radiograph. (1)

The

ratio

which

of an exposure

results

factor.

advantage

poor

image

definition applications.

occasions

when

formation

permits

during

also

be kept

only

when

free

and

the

Lead

alloy

The the

are tion

screens

screens

radiograph

back

trons

from

from

the

intensifies The

lead

released film

atoms

effect

when

electrons

are

of their

acted

is readily

of,

must

be touched

and

it must

commonly ability

used.

to absorb

the photographic is a result

upon

by high

absorbed

of the

pure contact

in most 0. 005 inch Lead

screens

scattered

radia-

effect

on the

release

energy

and

than

of radiation,

screen

screens

of elec-

radiation.

by the film

be

directions.

in close

energy

front

Front

to increasing

photographic

Energy

emulsion,

and

response.

intensification

fluorescent

because

in addition

must

is required,

the

The

screen.

thick

from

screens

manufacturer's

side

of

The surfaces

and

radia-

be prevented

of an antimony

on each

to

by blocking

resistant

specimen

back

exposed

more

thicknesses. the

con-

radiation.

caused

wear

only

to those

when

must

the

used

constructed

and

the

are

to low energy

if cleaning with

in pairs, upon

dust

is the inherent

specimen

graininess

sensitive

usually

0. 010 inch

efficient

increased the

used

than

screens

radiation)

The

are

the

surfaces.

and,

harder,

be of varying

particularly (soft

Their

screens

is thinner

and

stain.

is stiffer, are

dirt

and film

in accordance

Depending

may

and

film.

(1)

that

film.

applications thick

in the

necessary

strictly

Screens. lead

lead. with,

is restricted

screen

from

absolutely

accomplished Lead

the

however,

scattered

use

exposure,

between

to reduce

permitting

of their

is limited

their

shadows

This,

and

film

To prevent

misleading

use

excessive

thus

light

their

masking

cause

high energy radiation, tion applications.

emitted

Do

extensive

factor

screens

is required,

screens,

intensification

Because

fluorescent

Practically,

screens

collecting

of 95%.

screens.

exposure

with

the

intensification

magnitude

fluorescent

a short

is called

a high

characteristic,

in special

to an exposure

density,

have

of the

of using

Fluorescent

(2)

screens

in exposure

only

screens

of similar

Fluorescent

reductions

without

in films

screens.

factor

of lead

Under

screens

exposure

is much to low

energy

lower

than

radiation

that

of

it is 6-9

possible

for the

front

screen

that requiredexposure due to their capability and

the

resultant

absorption

is greater for reducing

better

contrast

and

lead screens are used wherever all gamma ray applications.

(2)

To insure

the

free

dirt,

from

intensification

tron absorption emitted by the

qualities screens.

tetrachloride wool

5.

absorbent

in the

masked

clay

erate

6. The

cause

definition

practice

since

screens

these

cleaning

abrasion

marks

no harmful that affect

image,

are

used

in almost

they

must

be kept

materials

thorough

radiographic

of covering,

material areas,

have

high

is desired, caused

elec-

electrons carbon fine

steel

by gently

rubbing

effects. Deep scratches, the flatness of the screen

gouges, surface

results.

or surrounding,

during

exposure.

eliminating

much

6-3), barium clay, material, it should greater

scatter.

radiation beam.

than

In any

by reducing

portions

Masking

scatter.

of the

reduces

the

Commonly

specimen

specimen

used

of the

specimen;

circumstance, the area

the

of,

or

the

purpose

the

materials

When barium clay absorption of

otherwise,

sole

about,

exposure

masking

and metallic shot (Figure 6-4). be thick enough so that radiation that

with

clay

will gen-

of masking

specimen

is to limit

exposed

to the

PENETRAMETERS penetrameter

is a device quality

or in establishing is a rectangle material

of metal

penetrameter

a.

level

image

(sensitivity).

with

three

is identified

thickness

for

which

holes

of set

similar,

by a lead

(T) of the

is used for

of discontinuities. drilled

the

on a radiograph It is not intended

limits,

or radiographically

of material The

whose

acceptance

identical,

thickness

to the

number

penetrameter standard

The

diameters as shown listed in Table 6-1.

in Figure

(ID No.)

being

which

is normally

Standard

in judging

the

gives

used.

is 2% of the

of

radiographed. the (See

maximum Figure

thickness

lx T (1T), 2xT has a 1.0 ID No.

penetrameter

size,

penetrameter

It is composed

material

penetrameter

6-5.

use

to determine

standard

diameter.

noted by the IDNo., and the hole diameters are 4 x T (4T). The standard 1.0 inch penetrameter

6-10

of the radiographic They

of lead

However, radiation

MATERIAL

is appreciably

radiographic

Each

fine

poor

noticeable

scattered primary

The

will

are lead, (Figure is used as a mask the

if a more

wool will have or depressions

is the

highly

and, be used.

lint

magnitude

and can absorb the "intensifying" The screens may be cleaned with

with steel wrinkles,

MASKING

Masking

may

and

to be of such

practicable.

action

grease,

effect

than that without screens. the effects of scattered

sizes

6-5.) de-

(2T), and and hole are

! t

MASKS

PRE-CUT

LEAD

SHEET

Figure b.

The penetrameter being radiographed. (usually the

of the

penetrameter)

6-3.

Lead

Masking

Technique

is normally placed source side on top of the specimen Thus, it is a built-in defect of known thickness

2% of Tm)

ability

MASKS

and

known

technique

and

hole

used

definition

(the

diameters.

to show hole

contrast

The (the

penetrameter thickness

measures of the

images).

SHOT

SPECIMEN

__

/

Figure _'_

6-4.

Masking

with

Metallic

FILM

Shot 6-11

1T .O2O"D

4T .O80"D

2T .O4O"D

V

1 :...,.,,-..-,..._ ...... . __.-,_'_:,:._, ..,..-. ........... :-- ..,. ,.-,.,....-.,.

:*.

.... "• "_.,-:_--.':._""

-..:,:.,;...%q

f.-

v,_'*_

a¢

,:.,-.w.',., """';"" ' 1_;-'4_':'.%_

_

l_;"._"

... ; -, ,- ....__---':'

-_

;-'_

\-%x,

:_t..._ _:.,... .¢;

,C?.. - .e ,':

....... -.. :V._,: .-,..,_}_-..._.

I .'_-..._'-'_,'_ "-."

, .-,,_

.-,._ .,.,- _ *_ ....... _.,

•; ;'.. _-.'._ w;;; k _y" .¢,

F_%-;., ,'-].-J,;

Tb--

IO NO.

.O2O"

Figure

6-5. Table

APPLIES TO DESIGN MATERIAL THICKNESS** (T m) UP TO AND INCLUDING (INCHES)

Standard 6-1.

Penetrameter

Standard

ID NO.

for

1" Material

Penetrameter

Sizes

;iT ii

1T HOLE DIA.

2T HOLE OIA.

4T HOLE DIA.

1/4"

0.25"

25

.005"

.010"

.020"

.040"

3/8

0.375

37

.DO8

.010"

.020"

.040*

1/2

0.5

50

.OlD

.OlD

.020

.040

5/8

O .625

62

.013

.013

.025

.O5O

3/4

O. 75

75

.015

.015

.030

.O6O

7/8

0.875

87

.018

.018

.035

.070

1.O

1.0

.020

.O2O

.040

.080

1-1/8

1

1.125

1.1

.023

.023

.045

.090

1-1/4

1.25

1.2

.025

.025

.050

.iOO

1-1/2

1.5

1.5

.030

.O3O

.060

.120

AND SO ON FOR EACH 1/4 INCH UP TO 2-1/2" UP TO 8", AND THEN IN 1" INCREMENTS.

AND THEN IN 1/2"

INCREMENTS

* MINIMUM HOLE SIZES REQUIRED BY THE STANDARD, DO NOT BEAR CORRECT RELATIONSHIP TO ID NO. OR THICKNESS OF THE PENETRAMETER. ** DEFINED AS THE THICKNESS OF THE MATERIAL (Tm) UPON WHICH THE THICKNESS OF THE PENETRAMETER IS BASED. FOR WELDS, THE MATERIAL THICKNESS SHALL BE THE THICKNESS OF THE STRENGTH MEMBER.

C,

Standard whose Other

6-12

2% sensitivity

thickness sensitivities

requires

the

technique

to image

the

penetrameter

is 2% of T m, and the 2T hole of the penetrameter (quality levels) are shown in Table 6-2. For

(penny). specimen

Table

_J

I-IT

1%

1T

1.0%

1-2T

1%

2T

1.4%

2-1T

2%

IT

2.0%

2-2T

2%

2T

2.8%

2-4T

2%

4T

4.0%

4-2T

4%

2T

that

Penetrameters

d.

as the

STOCK

stock

is defined

the

area

trameter

of the

of interest. the

FILM

Film

holders

They

are

are

the

HOLDERS are

made

flexible

and

specimen-to-film

usually

two-piece

screens

are

AND

and

the

Shims to the

is placed

specimen).

electronic

comthe

shim(s)

material. area

are

selected

specimen

to the

the

always

pene-

image

thickness

should

so that

(by the weld) the

way

They

of interest

underneath In this

equal

of the

such

of the

in the

area

be greater

than

CASSETTES

the

distance rigid

film film

light,

film firmly

and

including to the

holders

that

is not required

to protect

rubber

contours

at a minimum.

flexibility and

from

of materials

molding

together,

width

uses,

penny.

a variety

when

the

always

to determine

to specimen wherein

added

of material

to shield

hinged,

of use

and film

of the

permit

holding Cassettes

length

designed

from

and

a thickness

special

of small

thickness.

shim(s)

must

to as sensitivity.

identical

thickness The

penetrameter

through

dimensions

8.

the

6-6).

for

is designed

as welds,

specimen

penny

radiography

referred

such

equals

smaller

devised

the penny

of material

the

the

been

in the

usually

pieces

(Figure

the

In use,

similar

used

level,

sizes

have

however,

than

shim(s)

of interest

is projected

types

of specimens,

is thicker

(between

penny

as thin

in radiography

thickness

in the

penny

penetrameters quality

SHIM

radiographically

between

In all cases,

radiographic

used

are

of different

wire

ponents.

are

PENNY "T"

PERCEPT I BLE HOLE DIA.

thicknesses be used.

Shim

Levels

AS % OF T m

.7%

7.

Quality

QUALITY LEVEL

SENSITIVITY

!

6-2.

and plastic.

of the

Cassettes

clamping

holders

thereby

specially

tightly their

damage. The

specimen, are

spring-clamp since

it from

designed,

together. action

holds

in place. 6-13

I I

i I

I I

I

1

I

RADIATION I I

BEAM I I

I

I I

i I

1

I

,-P = PENNY /S

I

,I

= SHIM

FILM IF Tm = 1" AND REINFORCEMENT

BOTH

ROOT AND FACE IS 1/16", THE SHIM WOULD BE 1/8" OR THE DIFFERENCE BETWEEN T m AND Ts.

Figure 9.

LINEAR

Correct for

AND

ANGULAR

source-to-film

6-6.

of Shim

MEASURING

distance

any radiographic

Use

setup.

and

For

DEVICES

knowledge

these

of specimen

measurements,

and a tape measure are tools of the radiographer. at an angle other than that normal to the plane tractor

may

be used

t_o determine

Stock

the

a six-inch

of the

correct

thicknesses

required

machinist's

When a task specimen,

angular

are

requires a plumb

scale

radiography bob and pro-

setup.

V

1

10. For

POSITIONING quality

radiography,

specimen, the

and the

floor,

gamma

a table, ray

specially the

designed

radiograph

must

the

to,

fashion

with

the

with

with

marked

the

of the

(usually

fixed

during

exposure.

may

tripods)

This specimen pen, tape,

specimen

the

with

that

to position with

X-ray

the

equipment,

specimen.

With

of X-ray,

the cable

safety

radiograph,

specimen

exposure,

or by scribing. appear

used

the

ray),

and

containing

considerations,

that

MARKERS

finished

is accomplished

eliminates

With

is identical

are

or gamma

is acceptable.

of the

during

X-ray

to support

complying

AND ORIENTATION

that

suffice

specimen

radiation

be so marked

masking

(either

arrangement,

scatter

a marking

attached

source

surface,

interpretation

radiograph.

adjacent

6-14

holders

of the

remain

stable

support

IDENTIFICATION correct

position

should any

excess

To permit with

film or

Any positioning

not cause

11.

the

equipment,

source.

does

I_EVICES

on the

and

its

by affixing and

lead

radiograph.

any possibility

specimen

orientation

lead

marking

The

the

numbers

the numbers

specimen

the

be identified

or letters

to,

or

in identical

or letters,

Comparison of wrong

can

and

of the

identification.

which

are

radiograph

12. The

AREA control

Areas and

SHIELDING of scatter

in which back

by use

of lead

are

available, by the

behind,

the film

The

2-14

rooms

be adequately

lead

screens

shielded.

The

be covered

with

of shielding

protected When

this

permanent

and places area

techniques.

against

installations,

or compartments.

are

always

use

In permanent

uses

radiation

should

must

2-15).

radiographer

primary

only by proper

place

and

shielded

the

reached

is effected takes

(Figures

plished

13.

radiation

radiography

scatter

not

EQUIPMENT

both

side

is accominstallations

them

immediately

so that

areas

beneath,

or

lead.

DENSITOMETER densitometer

visual eter

and

electronic,

are

characteristic

similar 14.

is an instrument

important

will

similar

X-ray

exposure

kilovoltage, a certain certain

accurate, For

several

between

distance;

be used

which

only

chart

is based.

exposures

+- 10% since

when

most

distance

are

of uni-

radiographing

furnished

exposure

film

of film;

of specimens

a

by manufacturers

no two X-ray

X-ray

thickness,

of conditions: type

the

Charts

the

material set

a certain

as a guide

variations.

radiography,

different

exposures

of kilovoltages.

machines charts,

prepared

are

based

commonly

on the

used; for

resultant

Each

densities

corresponding thicknesses.

required

in routine

work

radiographs)

to locate

that

exists. correct

density

on each

When material

are

wedge

and an

each

X-ray

taken

of a step

desired

thickness

at each will

image

intensity

Choosing the

At each

density

does

for

density

in accordance

of the the

wedge X-rays

desired the

exposure, not appear

with

as a series trans-

density

uses point

at

of a selected

the

radiographer

of kilovoltage, that

is radiographed

is processed

radiograph.

value

the

film to the

wedge

a corresponding

The

radiograph

the

appears,

of radiographs

material.

(milliampere-minutes) The

procedures.

through

a series

specimen

work

of different

chart,

selected

routine

the

under

to a specific

to determine

target-to-film

number

ness

only upon

radiographed;

an exposure

of the

mitted

densitometer,

in use.

To prepare wedge

densitom-

used.

relationship

density

within

quality

chosen

machine

the

thickness

often

the

applies

adequate

but only

most

arbitrarily

show

but should

of wide

material

b.

are

thickness,

identical.

time

of densitometers,

is a desirable

A good

each

target-to-film

and

charts

specimen

Two types

Accuracy

is consistency.

chart

a certain

conditions;

form

available. readings

6-7)

Each

machine;

Exposure

are

(Figure

exposure.

X-ray

density.

CHARTS

charts

and

processing a.

give

EXPOSURE

measures

commerically

but more

conditions, X-RAY

that

(density

a densitometer desired

and

density

wedge

thick-

on a radiography,

is determined

by interpola-

f

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EXPOSURE IN ROENTGENS *WITH LEAD INTENSIFYING SCREENS

Figure

6-15.

Film

Characteristic

Curves

(Types

A,

B and

C) 6-33

1000 9 8

I IRIDIUM

192 EXPOSURE

! FACTORS FOR

7 EFX T '= --

D2 S

T -TIME (MINUTES) FOR DENSITY 2.0* EF-EXPOSURE FACTOR D -SOURCE-TO-FILM DISTANCE (FEET) S -SOURCE STRENGTH (CURIES)

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iv,

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*DENSITIES OTHER THAN 2.0 CAN'BE ORTAINED BY APPLYING THE FACTORS GIVEN BELOW. MULTIPLY THE EXPOSURE CALCULATED FROM THE FORMULA BY THE CORRECTION FACTOR INDICATED FOR THE DESIRED DENSITY. DENSITY

1.0

CORRECTION FACTOR

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Figure

e-s4

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Iridium

192

Exposure

Chart

2.0

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3,0

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1.62

--

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PERMISSIBLE

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FOR ISOTOPE INSPECTION (TWO PERCENT SENSITIVITY)

137

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2

SPECIMEN

4 THICKNESS,

5

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(INCHES)

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2000

1000

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90O 800 7OO

6OO

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500

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MAXIMUM

PERMISSIBLE

VOLTAGE

o ..I 400 (TWO

PERCENT

SENSITIVITY_

!

x