Fast-response resistive sensor of explosive concentrations of hydrogen (patented)

   A fast-response resistive sensor of explosive concentrations of hydrogen comprises an insulating substrate. A hydrogen sensitive thin-film element applied on the substrate, a heating member for preheating the hydrogen sensitive thin-film element, in which the hydrogen sensitive thin-film element is made of a material including at least palladium and subjected to heat treatment resulting in oxide formation, or of palladium oxide transferring from an oxide state to the metal state by the action of hydrogen.
   A method of using a resistive sensor of explosive concentrations of hydrogen consists in that the sensor is placed in a working volume, the temperature of the hydrogen sensitive thin-film element is set to be equal to the operating temperature and is kept at this level while monitoring its electrical resistance, at an increase of hydrogen concentration in the working volume, the dangerously explosive concentrations of hydrogen is recorded and the sensor performs the operating. The hydrogen sensitive thin-film element is made of a material containing palladium preheated to a temperature exceeding its operation temperature, the heat treatment continued until palladium oxide in a hydrogen sensitive thin-film element is formed, then the temperature is reduced to the operating temperature.
   After the sensor has performed the operating, the hydrogen sensitive thin-film element is repeatedly heated until palladium oxide is formed therein with a subsequent decrease of temperature to the working level, and this process is repeated after each operation of the sensor. In so doing the operating temperature of the hydrogen sensitive thin-film element is maintained within a range of 100°C to 150°C, and the heat treatment is effected at a temperature of 360°C to 400°C.
   The sensor is put in a working volume containing at least air, or nitrogen, or helium, or oxygen, or hydrocarbon, or noble gas.

RU Patent No 2221241 C1