Hydrogen gas detector industrial gas is used for refining petroleum products, producing fertilizer, processing metals and creating renewable energy. As a flammable compound, it’s also extremely dangerous when it accumulates in concentrations above 10% LEL (%LEL converts to 4,000 ppm). This growth of the hydrogen gas market has spawned increased demand for reliable monitoring equipment that can alert workers of a leak or accumulation of dangerous levels of the substance.

Several different technologies can be used to detect the presence of hydrogen gas. Some sensors use electrochemical methods based on surface redox reactions that generate currents proportional to the gas level. Other sensor technologies measure the gas using light. Fiber-optic and interferometric sensors use Bragg gratings that are characterized by a specific wavelength. When a hydrogen gas concentration interacts with the grating, a change in wavelength is observed, which indicates the presence of the contaminant.

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Heat conduction hydrogen sensors use a thermal material, often a Pt wire with high thermal conductivity, that reacts with the hydrogen gas as it flows past the sensor. This type of sensor is relatively simple and inexpensive to produce, but the sensitivity is not as high as other options and is affected by environmental variables like temperature and humidity. New sensor materials such as nanomaterials, hybrid carbons, two-dimensional materials and metal-organic framework materials are being researched to improve hydrogen sensing capabilities. These new materials are based on chemically active thin films that are able to change their properties when exposed to certain chemicals, including hydrogen. This change in property, known as a chemochromic effect, is detected by the sensor and can be used to alert personnel of a potential hazardous leak before it has a chance to cause an explosion or fire.