Answer question using formula sheet

Final Exam Sample Problems 1. The following are individual sound pressure levels measured for three equipment:

Equipment 1: 89 dBA Equipment 2: 90 dBA Equipment 3: 91 dBA Equipment 4: 92 dBA

Difference Between 2 Levels to be Added Amount to Add to Higher Level to Determine Sum 0 – 1 db 3 dB 2 – 3 db 2 dB 4 – 9 dB 1 dB

10 dB or more 0 dB a) Calculate the combined sound pressure level for all the equipment using the “rule of

thumb”.

b) Assuming that the combined sound pressure level is an 8-hr TWA noise exposure, is the exposure acceptable compared to the OSHA standard?

2. A worker’s exposure to radiation is 10 mR in 6 hours. To reduce his radiation exposure to 8 mR, for how many hours must he be exposed?

3. A worker’s exposure to radiation at a distance of 6 m from a radioactive source is 10 mR. To

reduce her exposure to 8 mR, what must be her distance (in m) from the radioactive source?

4. A worker’s exposure to radiation at a distance of 6 m from a radioactive source is 10 mR. If her

distance from the radiation source is reduced to 4 m, how much radiation exposure (in mR) will she obtain?

5. Outdoor workers perform their job for 7 hours in an 8-hr workday (1 hour of break) under direct sunlight. Workload is moderate.

Screening Criteria for TLV and Action Limit for Heat Stress Exposure

Allocation of Work in a Cycle of Work and Recovery

Work Load Light Moderate Heavy Very Heavy

TLV (WBGT values in °C) 75 to 100% 31.0 28.0 --- --- 50 to 75% 31.0 29.0 27.5 --- 25 to 50% 32.0 30.0 29.0 28.0 0 to 25% 32.5 31.5 30.5 30.0

Action Limit (WBGT values in °C) 75 to 100% 28.0 25.0 --- --- 50 to 75% 28.5 26.0 24.0 --- 25 to 50% 29.5 27.0 25.5 24.5 0 to 25% 30.0 29.0 28.0 27.0

a. Calculate the appropriate WBGT index given the following temperature measurements.

Calculate only one appropriate index:  Wet bulb temp = 29°C  Dry bulb temp = 35°C  Globe temp = 38°C

b. Is the measured WBGT index acceptable when compared to the ACGIH TLV? What TLV

value did you use?