Submitted to: Patent Application
Publication Type: Patent Application
Publication Acceptance Date: 10/31/2003
Publication Date: 5/18/2006
Citation: Pelletier, M.G. 2006. Multipath resistant microwave bale moisture sensor. U.S. Patent 7,078,913.
Interpretive Summary: Cotton bale degradation in storage is becoming a major problem to the U.S. textile industry (Brandon, 2003)(Anthony, 2003, 2003b). This degradation has been recently traced to excess moisture that is being added to the lint prior to baling (Anthony, 2003). The reason for this large influx of excess moisture is due, in part, to recognized advantages to adding moisture before the bale pressing operation as it reduces the pressure required to press the bale, thereby reducing wear and tear on the equipment. Unfortunately, while the technology to add the moisture to the bale is commercially available, to date, a low cost cotton bale moisture sensor to control these moisture restoration systems is not commercially available. The previous microwave bale moisture sensing invention is currently being marketed by Advanced Sensing and Controls Inc. This unit is being well received by the industry. This invention is a continuation of that work and improves upon the previous system by removing the field calibration requirement, thereby lowering the manufacturing costs which should translate to a lower market cost to the cotton gins.
Technical Abstract: The invention consists of a microwave based moisture sensor that has been optimized for use in metal clad structures which are typical of modern cotton gins. This system solves the problem of earlier inventions where in this type of environment, the microwave signals create standing waves which significantly alter the calibration of these sensing systems. This issue forces the installation process to either utilize costly anechoic material to remove these signals from the measurement, or as an alternative, requires a time consuming and expensive field calibration procedure. This invention solves this problem by utilizing a new technique that allows the system to electronically remove these multi-path signals from the measured signal, thereby removing the requirement of the installation calibration or the alternative anechoic material.