Influence of Temperature and Humidity on Partial Pressure Measurement using Dual Pressure Gauges

Taking into account the utilization of partial pressure measurement under various temperatures and humidity, their influence on this measurement with a capacitance manometer and a quartz friction pressure gauge (Q-gauge) is studied. With increasing humidity, a Q-gauge pressure reading, calibrated by air gas, decreases as well as when the hydrogen leakage is detected. To avoid this error by humidity for the hydrogen sensing, we tried to compensate influence of humidity using a humidity coefficient which is calculated from the humidity dependence of the Q-gauge pressure reading at constant temperature, and suppressed to one-fifth of the fluctuation of the Q-gauge pressure reading background due to humidity change. Regarding to influence of temperature on the Q-gauge pressure reading, it is calibrated by the temperature dependence at low humidity. Finally, influences of temperature and humidity on the hydrogen sensing can be reduced by the calculation below the reading by 0.6 at.% of hydrogen gas.