Abstract
The hydrogen gas sensor plays an important role in ensuring the safety of various industries that are heavily dependent on high-pressure hydrogen gas. A new type of hydrogen sensors, solid electrolyte, metal oxide semiconductor and other types are described. The gas sensor for hydrogen has the characteristics of the target gas (chemically active, good thermal conductivity, low viscosity, etc.), so it is also a sensor with the most detection principle compared to other combustible gases. Therefore, there are many other sensors at the level of practical application or in development. Experiments are currently underway on high-pressure hydrogen gas leaks and large amounts of hydrogen gas leaks, and some of them are obvious to the general public. There are several methods for detecting hydrogen gas, but it is not possible to use the infrared method, which has made significant technological advances in recent years, because hydrogen is considered a monoatomic gas, unlike methane. There are three types of hydrogen sensors included in practical use for safety reasons: they are catalytic combustion, semiconductor type and gas thermal conductor type. There are several types of semiconductor sensors, but here we will analyze hot-wire semiconductor sensors. In particular, it is characteristic of a high reaction with a wide concentration range and the like.