A new method of continuous measurement of the moisture content of chips
Yu. I. Merem'yanin · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1985
The new method is based on the frequency of the sound vibrations of chips as they move along a conveyor. The method is protected by Soviet Patent No. 1117514 (published in Byulleten' Izobr. 1984, No. 37). The accoustic properties of the normal chips are picked up by microphones; then a cooking gas (e.g. nitrogen) is fed into a chamber of sound-absorbing material, freezing the chips on the conveyor and changing their accoustic properties. The noise signals of the normal and the frozen chips are passed via selective amplifiers to a mixer which feeds them to a unit which measures the frequency difference, graduated in moisture content units. The relative error of the system is only about 4%; this is greatly superior to the dielectric method of moisture measurement commonly used in factories producing particleboards. (Refs. 4).