Select a hydrogen sensor. Hydrogen sensors can use electrochemical signals that are amperometric, potentiometric or solid/liquid electrolyte in nature to test the level of hydrogen gas in the air. MEMS (microelectromechanical systems) hydrogen sensors fall into this category and use nanotechnology to create hydrogen microsensors that function well at room temperature. There are also electronic and thermoelectric sensors that use palladium or palladium alloy film to test for the presence of hydrogen. Heated Metal Oxide sensors are available and are considered to be affordable by the National Renewable Energy Laboratory. Select the sensor that fits your budget and preference.
Test the functionality of your hydrogen sensor by conducting a test on a vessel filled with a mixture of 5% hydrogen and 95% nitrogen. This mixture ensures a non-flammable concoction that will provide a safe test of whether or not hydrogen is escaping the vessel into the laboratory. This is called a sniffing test.
Bring the sensor over to the vessel and use it to measure how much, if any hydrogen is leaking. Monitor your device carefully to determine whether or not a leak exists. Within one second, your device should give you a result of the hydrogen concentration in the air in a percentage of 0 to 100%.