Moisture determination of granular and solid materials - - by dielectric constant and phase shift measurements

摘要

The moisture content of granular and solid materials is determined by measuring the level of electromagnetic UHF waves passing through the material depending on the damping characteristics of the dielectric constant whereby additionally the phase shift of the dielectric constant is used. The instrument comprises an UHF generator executed as an UHF amplifier with a positive external feed back loop, in that the amplifier is coupled directly to a receiver and via a direct loop, directional feeder band filter and hollow connecting conductor to the transmitter, whereby the band filter is the frequency determining element and the feeder connects the recording facilities. Accurate, quick and reliable moisture determination are made by this method.