Humidity of gases measuring instrument - has two temperature sensitive resistors with the first resistor carrying a heating current

摘要

The resistors are placed in a closed chamber each, at least one of which is made of gas permeable film with an evaporation liquid supplied from a tank to an absorbent evaporation element which surrounds the first resistor in the gas permeable chamber. Resistances of the two resistors are compared. A display unit connected to the comparator displays the humidity of the ambient gas, proportional to the difference of the two resistances. The first resistor is supported by its leads without contact with solid parts of the instrument.