EPA 608 Core · Leak Detection · Hard
What is a 'trace gas' used in leak detection?
Answer: C. Nitrogen with a trace of the system's refrigerant.
- AA fluorescent UV dye added to the compressor oil.
- BPure R-22 used to test leaks on HFC systems.
- CNitrogen with a trace of the system's refrigerant.✓ Correct
- DOdorized propane injected into the system.
Why C is right
A trace gas is nitrogen mixed with a fraction of an ounce of refrigerant to trigger detectors.
More Core questions
- What is the most effective way to detect a massive system leak quickly?
- How does an ultrasonic leak detector find a leak?
- When searching for a leak with an electronic detector, how should the probe be moved?
- What gas should be used for safely pressurizing a system to leak test?
- Which leak detection method is best for pinpointing an exact leak location?
Go deeper with the study guide AIM Act 2026: The HFC Leak Repair Rules for HVAC Techs, try the free 10-question test or browse all EPA 608 practice questions.
A practice question written for study, checked against 40 CFR Part 82, Subpart F. It is not an official EPA exam question, and this site is not affiliated with the U.S. EPA.