Hydrogen Gas Sensing using Two Type of Pressure Gauges

For safety hydrogen sensing, the pressure measurement with a capacitance manometer and a quartz friction pressure gauge (Q-gauge) were investigated. Q-gauge pressure reading decreases when hydrogen gas is introduced into air supplied from atmosphere without any change of pressure measured by a capacitance manometer. This result indicates that the present pressure measurement using two pressure gauges is possible to detect the hydrogen leakage into air. In addition, a decrease of Q-gauge pressure reading correlates with a flow rate of the hydrogen gas, and increases with hydrogen concentration in air. Then it was shown that the low detection limit of hydrogen concentration is below 1%. Response time for hydrogen introduction is faster than 30 seconds, which meets the requirements for the hydrogen gas leak sensor. As above, the present safe pressure measurement using a capacitance manometer and a Q-gauge is satisfactorily useful for the hydrogen gas leak sensing.