Absolute humidity sensor and absolute humidity sensor chip used therefor

摘要

PROBLEM TO BE SOLVED: To provide an absolute humidity sensor as a heat conduction type sensor, allowing influence of ambient temperature to be corrected and dew point information and the like to be obtained, having high sensitivity, high accuracy, and high-speed response, and down-sized.SOLUTION: A heater and a thin film thermocouple as a temperature sensor are mounted on a thin film thermally separated from a base plate, the temperature of the thin film is made to reach different predetermined preset temperatures Tl, Th, comparison of power consumption of heating by the heater and comparison in time integration values of temperature sensor output in a cooling process after the stop of the heating by the heater are performed. The comparison of the power consumption for Tl, Th and the time integration output after the stop of the heating are performed by using a single thin film or two thin films having the same shape. There is provided an absolute humidity sensor which utilizes the deducted power consumption and the deducted integration value, corrects the ambient temperature including information of the absolute temperature of the base plate, and utilizes prepared calibration data. Moreover, information of dew point and the like is acquired from the response by minute power heating of the thin film. Also, a sensor chip suitable therefor is provided.