Apparatus for accurately measuring the water content of gas.

摘要

An apparatus for accurately measuring the water content of a moist gas containing less than 50 parts per million (ppm) of water comprises an isothermal heat-sink (14), a radiator (20), a Peltier heater-cooler (24) thermally arranged between the isothermal heat-sink (14) and the radiator (20). The heater-cooler (24) is transferring heat from the isothermal heat-sink (14) to the radiator (20) and vice versa. A phosphoric acid moisture cell (32) is in thermal contact with the isothermal heat-sink (14). Upon passing the moist gas through the cell (32) the amount of moisture in the moist gas is measured as variation of electrical current throughout the cell.