Miniaturized Pressure Sensor with Temperature Sensor for the Hydrogen Gas Environment

The authors have investigated a high-sensitive hydrogen pressure sensor at low pressure range. So far, we developed the vessel built-in type hydrogen pressure sensor element consisting of the zirconia structure body and the Cr-N thin film, which are not affected by hydrogen. In this study, we miniaturized the element to a 4 mm square and 3 mm thickness with a 2 mm diameter diaphragm. Its pressure response showed excellent linearity, sufficient sensitivity of about 1 mV/MPa, and stability with no significant change after 64 hours of holding at about 10 atm. In addition, a temperature sensor film was formed on the pressure sensor element, which enabled accurate simultaneous measurement of temperature changes in the pressure vessel. It can be expected as an unprecedented miniaturized pressure sensor with a temperature sensor that can be built into a pressure vessel, a joint or a pipe of hydrogen pressure system.