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Hydrogen leak testing is the normal way in which a hydrogen pressure vessel or installation is checked for leaks or flaws. There are various tests.

• The Hydrostatic test, The vessel is filled with a nearly incompressible liquid - usually water or oil - and examined for leaks or permanent changes in shape. The test pressure is always considerably more than the operating pressure to give a margin for safety, typically 150% of the operating pressure.

• The Helium leak test, The leak detection method uses helium (the lightest inert gas) as a tracer gas and detects it in concentrations as small as one part in 10 million. The helium is selected primarily because it penetrates small leaks readily. Usually a vacuum outside the object is created with an external pump.

• The Hydrogen microsensor, The object is filled with a mixture of 5% hydrogen/ 95% nitrogen, (below 5.7% hydrogen is non-flammable (ISO-10156). The handprobe connected to the microelectronic hydrogen sensors is used to check the object. An audiosignal increases in proximity of a leak. Detection of leaks go down to 5x10-7 cubic centimeters per second [1]. Compared to the helium test :The hydrogen is cheaper than helium, no need for a vacuum, the device is much cheaper,

Contents 1 Uses 1.1 Room testing 1.2 In-Line testing 1.3 Hand held testing 2 See also 3 External links

Stationairy unit, Hydrogen gas is only 7% the density of air, and thus rises. The hydrogen gas detector should be installed at the highest draft-free location in the room or compartment where hydrogen gas would accumulate.

A fixed stationary unit on the assembly line or installation.

A light mobile point-contact sensor

Hydrogen Concentrations of 4% to 75% mixed with air (around 40,000 ppm) can be explosive.

• Hydrogen analyzer
• Hydrogen piping
• Tubing (material)
• Hydrogen station

• Fibre gratings for hydrogen sensing
• Wide-Range Hydrogen Sensor
• Wireless sensor