Electronic Instrumentation for Sensing Humidity in Wide Range
Tsuyoshi Matsui, Hiromi Eguchi, Keiichiro Mori, Taisuke Irie · Seibutsu kankyō chōsetsu/Seibutsu kankyou chousetsu · 1979
For the humidity control in wide range, an instrumentation was developed for sensing the humidity with the use of electric capacitance. The probe used was Brady rray BR-101B (Thunder Scientific Corp.) in which the electric capacitance was changed by humidity and temperature. The capacitance was converted to voltage, and equation (4) was presented for calculating the humidity as a function of output voltage and temperature. In this system, it was made possible to measure the humidity in temperature range of 0°C to 40°C by obtaining digital and analog outputs of relative humidity, absolute humidity and saturation deficit. Thus, the humidity was measured in wide range, especially in lower temperatures with reliable characteristics, and the humidity control in lower temperatures became possible by means of using this system as a feedback sensor.