What attributes are important for a hydrogen leak detector? What concentration of hydrogen is the normal set point?

Speed of detection, detection limit, location, and cross-sensitivity are some of many criteria that might be used for selecting a detector. A common setpoint for gaseous hydrogen detection is 25% of LFL, or 1% concentration in air. However, the detection limit also depends on the system and exposure. When specific hazards are likely, detectors may have detection limits in the low-ppm range. Lower detection limits can offer earlier detection, but also at the risk of spurious trips.