EPA 608 609 Leak Detection and Repair 3 — Questions and Answers
Question 1: An electronic leak detector responds to which characteristic of refrigerant?
- Its color
- Its presence in the air near a leak (Correct answer)
- Its weight
- Its boiling point
Correct answer: Its presence in the air near a leak
Electronic detectors sense refrigerant vapor concentration in the air near a leak.
Question 2: What is the EPA annual leak rate trigger for industrial process refrigeration?
- 20%
- 25%
- 30% (Correct answer)
- 40%
Correct answer: 30%
Industrial process refrigeration must be repaired when the annual leak rate exceeds 30%.
Question 3: Before electronic leak detection, why should the area around suspected leaks be free of strong air currents?
- Air currents corrode the sensor
- Air currents disperse escaping refrigerant and cause false negatives (Correct answer)
- Air currents increase pressure
- Air currents add moisture
Correct answer: Air currents disperse escaping refrigerant and cause false negatives
Drafts disperse the leaking vapor, making it harder for the detector to sense.
Question 4: A halide torch leak detector indicates a refrigerant leak by changing what?
- Flame color to green (Correct answer)
- Pitch of a sound
- Pressure reading
- Dye fluorescence
Correct answer: Flame color to green
A halide torch flame turns green when it contacts chlorinated refrigerant.
Question 5: How often must comfort cooling appliances with leaks exceeding the trigger rate be checked under recordkeeping rules?
- Documented and repaired within the required timeframe (Correct answer)
- Never documented
- Only at end of equipment life
- Only when sold
Correct answer: Documented and repaired within the required timeframe
Leaks must be documented and repaired within the EPA-required timeframe.
Question 6: When using nitrogen to pressure-test, a technician should always do what to control the pressure?
- Open the tank fully
- Use a pressure regulator (Correct answer)
- Heat the cylinder
- Bypass the gauges
Correct answer: Use a pressure regulator
A pressure regulator is required to keep nitrogen below the system's test pressure limit.
Question 7: What is the primary advantage of fluorescent dye over a soap-bubble test for small, slow leaks?
- Dye is cheaper to buy
- Dye remains in the system and reveals intermittent or hidden leaks over time (Correct answer)
- Dye repairs the leak
- Dye requires no inspection
Correct answer: Dye remains in the system and reveals intermittent or hidden leaks over time
Dye stays in the system and marks even slow or intermittent leaks for later UV inspection.
EPA 608 609 Leak Detection and Repair 3
An electronic leak detector responds to which characteristic of refrigerant?