The Restek electronic leak detector will detect minute leaks of any commonly used carrier, fuel, or make-up gas with a thermal conductivity different from air. The reference gas inlet on the back of the leak detector draws in ambient air for comparison to the gas sample drawn into the sample probe stylus. A thermal conductivity difference between the two indicates a leak, and the leak is revealed by both an LED display and an audible tone.
| Gas | Min. Detectable Leak Rate (atm cc/sec.) | Indicating LED Light Color |
| Helium | 1.0 x 10-5 | Red |
| Nitrogen | 1.4 x 10-3 | Yellow |
| Argon | 1.0 x 10-4 | Yellow |
| Carbon dioxide | 1.0 x 10-4 | Yellow |
| Hydrogen* | 1.0 x 10-5 | Red |
*Caution: The Restek electronic leak detector is designed to detect trace amounts of hydrogen in a noncombustible environment. It is NOT designed for determining leaks in a combustible environment. A combustible gas detector should be used for determining combustible gas leaks under any condition. When using it to detect hydrogen, the Restek electronic leak detector may only be used for determining trace amounts in a GC environment.
