Moisture meter

A meter for measuring the dielectric constant of a predetermined amount of material constituting a sample to determine the moisture content thereof comprising:

• a capacitor having means to receive the sample, a stable reference frequency means, a phase comparator, and a voltage controlled oscillator interconnected to form a phase-locked loop frequency controller;
• the voltage controlled oscillator being connected to the capacitor to detect a change in capacitance causing the voltage controlled oscillator to change frequency which due to the phase-locked loop condition causes the ouput of the phase comparator to change and maintain the frequency of the voltage controlled oscillator at the frequency of the stable reference frequency means;
• the phase comparator output being proportional to the moisture content of the material;
• and,
• indicating means connected to the phase comparator and responsive to the output of the phase comparator to indicate the moisture content.