probe gas

probe gas

[′prōb ‚gas]
(engineering)
Tracer gas emitted from a small orifice for impingement on a restricted area being tested for leaks.
References in periodicals archive ?
Investigators Probe Gas Leaks at South Carolina Apartment Complex
The concentration of the probe gas was followed by a NO/N[O.sub.2] analyzer in the dark until equilibrium was reached.
For this investigation, we prepared two different Ti[O.sub.2] foams (using different amphiphilic molecule) and change the amount of the probe gas (NO) during the photoassisted oxidation.
This allows us to probe gas in foreground galaxies.
Their varying response to different gas species makes them into practical leak detectors since a probe gas other than air, such as helium, will produce a sudden and large reading difference.
This attribute has helped give rise to a particular piece of technological folklore that helium (He) is used as a probe gas for leak detection because it is a small molecule and more able to pass through a leak.
Leak detectors can detect leaks only if helium probe gas is allowed to enter the sensing head.