Physical quantity measurement system

Abstract

The present disclosure addresses the problem of measuring hydrogen concentration with high accuracy. A physical quantity measurement system (1) includes a concentration measurement unit (205) and a flow rate measurement unit (206). A concentration measurement unit (205) measures a water vapor concentration of water vapor contained in the mixed gas and a gas concentration of a gas that is contained in the mixed gas and is different from the water vapor. A flow rate measurement unit (206) measures the flow rate of the mixed gas and the flow rate of the gas contained in the mixed gas. A concentration measurement unit (205) calculates the water vapor concentration using the pressure of the mixed gas and the humidity measurement value and the temperature measurement value of the water vapor measured by the temperature / humidity sensor (16). A concentration measurement unit (205) calculates the gas concentration using the water vapor concentration, the propagation time of the ultrasonic waves, and the temperature of the mixed gas measured by temperature sensors (for example, temperature sensors 13, 14). A flow rate measurement unit (206) calculates the flow rate of the mixed gas using the pressure of the mixed gas, the water vapor concentration, the gas concentration, and the flow rate coefficient. The flow coefficient is a value based on the kinematic viscosity of the mixed gas.

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