A Portable Solid-State Moisture Meter For Agricultural And Food Products
C.R. Bull, John V. Stafford, G.S. Weaving · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1988
This paper reports on the development of a small, robust, battery operated near infra-red (NIR) reflectance device, designed for rapid on-farm measurement of the moisture content of forage crops without prior sample preparation. It has potential application to other agricultural or food materials. The instrument is based on two light emitting diodes (LEDs), a germanium detector and a control CMOS single chip microcomputer. The meter has been calibrated to give a direct read out of moisture content for 4 common grass varieties at 3 stages of development. The accuracy of a single point measurement on a grass sample is approximately ± 6% over a range of 40-80% (wet basis). However, the potential accuracy on a homogeous sample may be as goon as 0.15%.