• Author / Uploaded
• Alex Dacayanan

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SAMPLE SOLVED PROBLEMS 1. In the Dorben company, an Industrial Engineer designed a workstation where the seeing task was difficult because of the size of the components going into the assembly. The desired brightness was 100 foot lamberts and the workstation was painted a medium green having a reflectance of 50 percent. What illumination in foot candles would be required at this workstation to provide the desired brightness? Estimate the required illumination if you repainted the workstation with a light cream paint. SOLUTION : Illumination (Medium Green) = luminance/reflectance = 100 fl/0.50 = 200fc Illumination (Light Cream) = luminance/reflectance = 100 fl/0.75 = 133fc 2. In the Dorben company, an all-day study revealed the following noise sources : 0.50 hours, 100 dBA; 1 hour, 95 dBA; 3.5 hours, 90 dBA; 3 hours, 92 dBA. What is the dose exposure? Is this company in compliance? SOLUTION : D = 100 x (0.50/2 + ¼ + 3.5/8 + 3/6) D = 143.75

3. What is the luminance of a surface having a 50% reflectance and 4 foot candle illumination? Luminance = Illuminance x reflectance = 4 x 0.50 = 2 fL

4. A worker is exposed to one hour at 80dBA, four hours at 90dBA, and three hours at 96 dBA. The worker is permitted 32 hours for the first exposure, 8 hours for the 2nd exposure, compute the allowable hours for the 3rd exposure. Allowable hours for 3rd exposure T = 8/2 (96-90)/5

= 3.48 hours

5. Compute for the visual angle for an objects height of 20 inches with an optimal distance of 45 inches. 3438 x h/d = 3438 x (20/45) = 1,528 arc minutes