"A capacitive polymer humidity sensor is a special type of humidity sensor based on the use of polymeric materials to detect changes in humidity. The sensors utilize the properties of polymers that react to moisture and thereby influence the capacitance of the sensor. The evaluation electronic convert the capacitive value into humidity value.

The HygroMer WA-1 sensor is based on the HygroMer IN-1, but in a smaller design for measuring water activity in moderate temperatures."