Calibration of dielectric constant probes using salt solutions of unknown conductivity

A new procedure for calibrating dielectric constant sensors was developed which used air, distilled water, and two saline solutions as references but did not require knowledge of the loss factors of the saline solutions. The use of the saline solutions was necessitated when a short circuit was found to be unsatisfactory as a calibration reference. When properly calibrated and handled, a set of gold-plated sensors measured dielectric constants to /spl plusmn/1% or better over a range of 50 to 150 MHz. The precision of the sensors declined below 50 MHz.