Which instrument detects the trace gas used in leak detection?

• A. Ultrasonic Leak Detector
• B. Microfoam Solution
• C. Electronic Leak Detector
• D. Trace Gas Detector

Answer: (C)

Detecting leaks that use a trace gas relies on a sensor that responds to very small amounts of that gas in the air. An electronic leak detector is designed to sense trace concentrations of common leak gases (like helium or refrigerants) and provide a reading or warning when the gas is detected, allowing you to follow the leak path precisely. The other options don’t sense the gas itself: ultrasonic devices listen for the sound of a leak, a microfoam solution shows a leak visually on surfaces, and while a trace gas detector can detect gas, it isn’t the standard instrument used specifically for locating leaks in many practical leak-detection tasks. So the electronic leak detector is the tool that directly detects the trace gas used in leak testing.