Continuous action capacitive moisture measuring apparatus

摘要

Capacitive moisture measuring apparatus for continuously measuring the moisture content of granular material, such as grain, includes a series circuit including a measuring capacitor whose capacitance varies as a function of moisture content of granular material in which it is immersed during operation and a resistor coupled to the measuring capacitor, and an oscillator for generating a voltage signal of stable frequency and amplitude which is applied to the circuit. An operational amplifier is serially coupled to a diode to constitute an ideal diode, the latter being coupled across the measuring capacitor.