THERMAL MASS FLOW METER WORKING ACCORDING TO THE DIFFERENTIAL PRINCIPLE OF ELECTRICITY

摘要

The disclosed mass flow transducer is of the type including a balanced bridge comprising two, substantially identical, thermal elements forming two sides of the bridge between the top and the bottom of the bridge, the two elements being adapted to be positioned in two regions of a laminar flow tube in a symmetrical tandem arrangement so as to sense flow through the tube, one element being upstream from the other. The preferred transducer includes control means for monitoring the voltage at the top and bottom of the bridge and monitoring the current required to maintain the node between the thermal elements at virtual ground.