Novel circuit for the rapid measurement of dielectric constant with ultra precision over a wide range of frequencies

Preparation and use of a circuit for establishing the dielectric constant for high and low conduction materials are presented. Crystals exhibiting the piezoelectric effect are sawn and polished to fix the frequency and inserted into a condenser chain of a modified Hartley oscillator. Capacitance is determined when the crystal shows a sudden increase in resonance due to energy absorptance corresponding to a shadow angle setting in a 6E5 tuning indicator tube. The dielectric constant then becomes a ratio of capacitance in a gas or a liquid medium to capacitance in a vacuum and analytic means to account for stray capacitance are developed. Changes in capacitance are accurate to 1 in 500,000 and frequency can be fixed to 1 in 1,000,000. The effects of a nonpolar solvent on the magnitude of the measured electric moment of a solute molecule can be determined as can the dipole moments of less polar molecules such as chloroform.