Gas detection systems can be designed to be either detect at the source of the gas, or can be designed as a sampling system. Putting a sensor as close as possible to the source of the gas is the fastest way to detect a leak. Sampling systems add a significant amount of lag time, or sampling time, to bring a sample of a gas to the sensor.
Sampling systems require additional on-going maintenance when compared to putting a sensor near the source of a leak – pumps have to maintained, tested, and rebuilt/replaced; sampling lines have to be routinely tested for leak; and bump testing and calibration have to be done from the end of the sampling tube, making this a 2 person job instead of a single person job. Sampling systems have their place for special applications – pulling a sample from a clean room, pulling a sample
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