Hydrogen impurity testing system and hydrogen impurity testing method

A hydrogen impurity testing system comprising:

• a sensor unit installed in an atmosphere with highly concentrated hydrogen containing toxic impurities;
• a heater unit capable of heating the sensor unit;
• a system controller applying a voltage to the sensor unit to measure a flowing electric current and controlling at least the sensor unit and the heater unit;
• wherein the heater unit comprises
• a semiconductor substrate,
• an impurity layer of a first conductivity type formed on a surface of the semiconductor substrate,
• a metal oxide layer formed on the surface of the semiconductor substrate, and
• a metal electrode layer, which is made of a metal having adsorption sites for hydrogen and toxic impurities, formed on the metal oxide layer and exposed to the atmosphere to be able to adsorb the toxic impurities, and
• the system controller detects a concentration of the toxic impurities by measuring change in work function of the metal electrode layer according to type and concentration of the toxic impurities and, based on results of detection, performs a refresh by heating the metal electrode layer with the heater unit to desorb the toxic impurities adsorbed on the metal electrode layer.