A technician adds fluorescent dye to a system and later scans the joints. What is used to find the leak?
Refrigeration · EPA 608 Core. The correct answer, and the reasoning behind it.
The refrigeration cycle, refrigerant states and pressures, gauges and leak detection.
The question
A technician adds fluorescent dye to a system and later scans the joints. What is used to find the leak?
- A black (ultraviolet) lightCorrect answer
- A halide torch flame
- A micron gauge
- A sight glass
Why “A black (ultraviolet) light” is correct
Fluorescent dye travels with the refrigerant and oil and collects where they escape. Under a black (ultraviolet) light the dye glows, showing the exact leak point. Like bubble solution and electronic detectors, it locates a leak rather than only showing that one exists.
Source: EPA: Test Topics
Why the other answers are wrong
- A halide torch flame — A halide torch is an old flame-based detector and is not used to see dye.
- A micron gauge — A micron gauge measures deep vacuum, not leak location.
- A sight glass — A sight glass shows liquid flow, not the location of a leak.
Practice more of this
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