A diaphragm impact sensor for measuring combine grain flow

A diaphragm-based grain flow, sensor has been developed for use on a grain combine. The diaphragm sensor is similar to conventional impact flow sensor s, but it uses a flexible fabric-reinforced rubber diaphragm to isolate the grain from the load cell that measures the impact force. The original geom etry of the elevator delivery area is preserved, no plates or other devices protrude into the grain flow. Accuracy of the sensor was determined by com parison to a catch bin and a weighing conveyor: The relationship between im pact force and grain flow was linens at high grain flows, but somewhat non- linear at low flow rates. Diaphragm life has exceeded 6800 Mg (250, 000 bus hels).