Practice Test GeeksG3 - Gas Technician Level 3 Certification Practice Test
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Leak Detection and Testing Procedures Flashcards

7 cards from real G3 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Leak Detection and Testing Procedures flashcards as text

  1. Electronic combustible gas detectors measure gas concentration as a percentage of which value?

    Answer: Lower explosive limit (LEL)

    Electronic gas detectors display readings as a percentage of the Lower Explosive Limit (LEL), alerting technicians before concentrations reach dangerous levels.

  2. What type of electronic leak detector is best suited for detecting very small leaks in high-pressure gas distribution mains?

    Answer: Flame ionization detector (FID)

    Flame ionization detectors (FID) have extremely high sensitivity and are ideal for detecting very small hydrocarbon gas leaks in distribution mains.

  3. Under CSA B149.1 Natural Gas and Propane Installation Code, which test medium is NOT acceptable for leak testing gas piping?

    Answer: Oxygen

    Oxygen must never be used as a test medium because it creates an explosive mixture with any combustible gas residue in the piping.

  4. When using an electronic leak detector in a confined space, the technician should check gas concentration at which level first?

    Answer: It depends on the specific fuel gas being tested

    The testing level depends on the fuel gas: natural gas (methane) is lighter than air and rises to the ceiling, while propane is heavier and sinks to the floor.

  5. A G3 technician is called to a suspected gas leak. What is the FIRST action upon arriving at the scene?

    Answer: Eliminate all ignition sources and ventilate the area

    Eliminating ignition sources and ventilating the area are the first priority to prevent ignition of any accumulated gas before testing begins.

  6. Which instrument is used to measure gas pressure with the highest accuracy for low-pressure systems operating at or below 14 in. W.C.?

    Answer: Slant-tube manometer

    A slant-tube manometer provides the highest accuracy for low-pressure measurements because the inclined tube magnifies small pressure differences for easier reading.

  7. When testing a gas system that has been out of service for an extended period, why must the system be purged before returning to service?

    Answer: To displace air or inert test gas that could create a flammable mixture at the burner

    Purging removes air or inert test gas that could form a flammable air-gas mixture at burners during ignition, creating a safety hazard.