Title :
A digital hygrometer
Author :
Shimizu, Hiro ; Matsumoto, Hiroki ; Asakura, Masahiro ; Watanabe, Kenzo
Author_Institution :
Kurabe Ind. Co. Ltd., Hamana, Japan
fDate :
6/1/1988 12:00:00 AM
Abstract :
A digital hygrometer using a polyimide capacitive humidity sensor is developed. The capacitance change of the sensor due to adsorption of water vapor in the atmosphere is detected by a switched-capacitor digital capacitance bridge controlled by a one-chip microcomputer and is displayed as relative humidity with 0.1% resolution. The accuracy of the hygrometer calibrated by a two-point method is solely determined by the temperature dependence and the long-term drift of the dielectric sensitivity of the sensor and is estimated to be 2%
Keywords :
bridge instruments; computerised instrumentation; digital instrumentation; electric sensing devices; hygrometers; microcomputer applications; polymers; switched capacitor networks; adsorption of water vapor; capacitive humidity sensor; dielectric sensitivity; digital hygrometer; electric sensing devices; long-term drift; one-chip microcomputer; polyimide; polymers; switched-capacitor digital capacitance bridge; temperature dependence; two-point method;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
