WIDE RANGE. LOW FLOW RATE OF DECAY, TEMPERATURE DETERMINATION FLOW CONTROLLER

摘要

Mass flow control methods and systems are described enabling rate of decay measurements with an orifice (or flow restrictor) located between the control volume and the outlet valve such that the outlet valve acts as the valve restricting backpressure. The system may include a main flow path and a reduced flow path that split the gas flow based on the received set point and backpressure. Measuring valve coil temperature may be used by measuring voltage and current of the valve of known resistance at room temperature and using copper coefficient of thermal resistivity delta. This temperature data may improve adjacent transducer temperature data and adjust the transducer output. Flow calculation during a long ROD pressure drop (in reduced flow rate) by making smaller flow calculation during sub section of the same, adjusting the control loop of delivered flow in real time while the ROD is still going and repeating.