Leak detection with Hydrogen

In the past, leak detection with the search gas hydrogen was of little significance, because of the dangers involved with this gas. In the meantime a semiconductor sensor has been developed which can measure hydrogen concentrations down to 0,5 ppm. The hydrogen content in the atmosphere is also only 0,5 ppm (ten times lower than the background of helium). Therefore it becomes interesting to search for leaks with a test gas mixture of 5% hydrogen and 95% nitrogen. This gas mixture is neither inflammable nor explosive.

The use of hydrogen as a future source of energy has already initiated applications such as fuel cells, hydrogen motors etc. which are filled with & driven by this gas. Thus the use of hydrogen as a sensor is an ideal solution for leak testing. Mass spectrometer leak detectors can be calibrated for hydrogen, but a simpler solution is to employ the semiconductor sensor, which detects hydrogen without the need for vacuum.

For leak location with this method only the sniffer method is possible and for integral leak test only the method inside out is possible, as been described under helium integral test for large test objects.