Which device can be used to pinpoint a leak?

• A. Combustible gas indicator (CGI)
• B. Digital multimeter
• C. Smoke pen
• D. Ultrasonic leak detector

Answer: (A)

The key idea is using a device that directly senses the presence of combustible gas to locate where it’s escaping. A combustible gas indicator (CGI) detects hydrocarbon vapors in the air and responds when it detects gas, allowing you to sweep along hoses, fittings, regulators, and connections. As you move the probe across suspected areas, the readings rise or the detector beeps, pointing you to the exact spot of the leak. This direct gas-sensing approach makes it quick and reliable to pinpoint a propane leak source.

Other tools don’t target the problem as directly. A digital multimeter measures electrical values, not gas leaks. A smoke pen can help visualize airflow in some situations but doesn’t reliably reveal hydrocarbon leaks and isn’t as definitive for pinpointing a leak in a propane system. An ultrasonic leak detector listens for high-frequency noise from a leak, but propane leaks don’t always produce a detectable ultrasonic signal and it can be less straightforward to interpret in a real-world setting.

So, for directly locating a propane leak, the combustible gas indicator is the best-fit tool. Remember to follow safety procedures—ventilate the area, avoid sparks or flames, and handle the system according to proper propane-handling guidelines.