G3 Leak Detection and Testing Procedures 2

Question 1

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

Accepted Answer

Lower explosive limit (LEL)

Answer

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

Question 2

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

Accepted Answer

Flame ionization detector (FID)

Answer

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

Question 3

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

Accepted Answer

Oxygen

Answer

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

Question 4

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

Accepted Answer

It depends on the specific fuel gas being tested

Answer

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.

Question 5

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

Accepted Answer

Eliminate all ignition sources and ventilate the area

Answer

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

G3 - Gas Technician Level 3 Certification Practice Test

G3 - Gas Technician Level 3 Certification Practice Test

G3 Leak Detection and Testing Procedures 2