Thin palladium film as a sensor of hydrogen gas dissolved in transformer oil

A sensor for the detection of hydrogen gas dissolved in the transformer oil is proposed. The absorption of hydrogen in thin palladium film causes changes in the electrical and optical properties of the film. The proposed structure can be simultaneously used as a resistance and optical sensor. The sensor has been tested for different hydrogen concentration and in different temperatures. The hydrogen concentration was varied from 200 to 1500 ppm (in the transformer oil) and the oil temperature was changed from 20 to 120 °C. The sensor exhibits good sensitivity for low hydrogen concentration and the long-term stability of parameters in the transformer oil up to 90 °C. The sensitivity and the reaction time of the sensor strongly depend on the operation temperature. It should be possible to use such a sensor structure for the continuous monitoring of electric power systems.