Sensor device for particles in an air steam

Abstract From the Canadian patent

The blockage module is designed to be mounted on air seeder seeding equipment. Piezoelectric sensors extending into the flow tubes monitor flow by producing high frequency ringing signals when struck by seeds. During a calibration step the module will monitor each, sensor and adjust the gain of the signal until the number of seed hits per second above a fixed voltage threshold is near a predetermined value. Each sensor connected to the module will be similarly calibrated and the cali-, brated gain and hit rate will be stored. It has been found that if a blockage or partial blockage occurs under these calibrated conditions, the number of hits above the fixed voltage threshold will be sharply …