CPE CPE Environmental Ergonomics Questions and Answers 2 — Questions and Answers
Question 1: The predicted mean vote (PMV) index by Fanger predicts thermal comfort based on how many variables?
- 2
- 4
- 6 (Correct answer)
- 8
Correct answer: 6
Fanger's PMV model uses six variables: air temperature, radiant temperature, air velocity, humidity, metabolic rate, and clothing insulation (clo).
Question 2: What is the primary ergonomic concern with vibration frequencies in the range of 4–8 Hz for seated workers?
- Risk of hand-arm vibration syndrome
- Resonance with the lumbar spine, increasing injury risk (Correct answer)
- Disruption of visual acuity
- Thermal discomfort from friction
Correct answer: Resonance with the lumbar spine, increasing injury risk
The 4–8 Hz frequency range resonates with the lumbar spine and abdomen of seated workers, amplifying internal vibration and increasing low back disorder risk.
Question 3: Carbon dioxide (CO2) concentration in an office space above what level is considered an indicator of inadequate ventilation?
- 400 ppm
- 800 ppm
- 1,000 ppm (Correct answer)
- 2,000 ppm
Correct answer: 1,000 ppm
ASHRAE guideline 62.1 uses 1,000 ppm CO2 as an indicator that outdoor air ventilation is insufficient, correlating with increased occupant complaints.
Question 4: Illuminance is measured in which unit?
- Candela (cd)
- Lumen (lm)
- Lux (lx) (Correct answer)
- Nit (nt)
Correct answer: Lux (lx)
Illuminance is the amount of light falling on a surface, measured in lux (lx) where 1 lux equals 1 lumen per square meter.
Question 5: Heat acclimatization for workers newly exposed to hot environments typically requires how many days to achieve significant physiological adaptation?
- 1–3 days
- 7–14 days (Correct answer)
- 21–30 days
- 60 days
Correct answer: 7–14 days
Meaningful heat acclimatization — including improved sweating efficiency and cardiovascular adaptation — typically requires 7–14 days of progressive heat exposure.
Question 6: Which OSHA standard establishes the permissible exposure limit (PEL) for occupational noise?
- 29 CFR 1910.95 (Correct answer)
- 29 CFR 1910.134
- 29 CFR 1910.147
- 29 CFR 1910.1000
Correct answer: 29 CFR 1910.95
OSHA 29 CFR 1910.95 (Occupational Noise Exposure) establishes the 90 dBA 8-hour TWA PEL and requirements for hearing conservation programs.
CPE CPE Environmental Ergonomics Questions and Answers 2
The predicted mean vote (PMV) index by Fanger predicts thermal comfort based on how many variables?