Electronic Scale for Measuring Mass Flow

摘要

An electronic scale which measures small rates of mass flow (~1.5 x 10 * lb/sec) from a large gross weight (250 lb) is described. Four meters indicate the gross weight of the sample and container, sample weight loss, rate of weight loss, and deviation of rate of weight loss from a preset desired rate.nIn operation, a semiconductor load cell senses the gross weight. The output of the load cell is amplified to produce an analog signal proportional to the gross weight. This signal is differentiated electronically to produce the rate of mass flow information in units of 0.1 lb/10 min. An additional output circuit shows the deviation of the rate of mass flow from a present desired rate.