A Novel humidity sensor with a constant temperature measurement mechanism

We present a humidity sensor with a constant temperature measurement mechanism to ensure both the elimination of the ice on the surface of the sensor and the controllable temperature of the sensor chip in the low ambient temperature condition. In this humidity sensor, the capacitive type humidity sensitive unit is located at a suspended membrane, and the lower electrode of humidity sensitive unit has two very important roles in the sensor: one is the lower electrode of capacitor, the other one is the controllable heater. The test result of this humidity sensor shows that the sensor has a wide range of sensing ambient relative humidity from 25%RH to 95%RH, and can work in a controllable constant temperature in different ambient temperature environment.