Transient Humidity Measurements—Part I: Sensor Calibration and Characteristics

In this paper, a transient test facility is used to investigate the transient response of a polymer film electronic humidity sensor (capacitance type) following a step change in humidity and temperature. The response of the humidity sensor is measured for a step change in the humidity with and without a change in temperature, and the data are correlated with exponential functions with two time constants. The major time constant of the sensor is about 3 s for the isothermal test but increases by an order of magnitude when the sensor is exposed to a simultaneous change in temperature and humidity