SYSTEM AND METHOD FOR USING A RATE OF DECAY MEASUREMENT FOR REAL TIME MEASUREMENT AND CORRECTION OF ZERO OFFSET AND ZERO DRIFT OF A MASS FLOW CONTROLLER OR MASS FLOW METER

摘要

The disclosed embodiments include a method, apparatus, and computer program product for providing a self-validating mass flow controller or mass flow meter. For example, in one embodiment, a self-validating mass flow controller is disclosed that does not require any software modification to a tool/tool controller in which the mass flow controller is being utilized. In other embodiments, a self-validating mass flow controller is disclosed that does not require any hardware or mechanical changes to an existing mass flow controller. Still, the disclosed embodiments further include a self-validating mass flow controller that is configured to determine valve leak and sensor offset simultaneously for performing real time in-situ correction of a mass flow controller's output for zero offset or zero drift in the presence of valve leak.

主权项

1. An apparatus comprising:
an inlet for receiving the fluid; a flow path in which the fluid passes through; a mass flow sensor for providing a signal corresponding to mass flow of the fluid through the flow path; a pressure transducer coupled to the flow path configured to measure pressure at a point in the flow path; a communication interface for communicating with a tool controller; and at least one processing component configured to execute instructions to:
perform an in-situ rate of decay measurement;determine a first valve leak value based on the rate of decay measurement;perform a flow measurement using the flow sensor while performing the in-situ rate of decay measurement;determine a second valve leak value measured by the flow sensor;determine a sensor offset correction value based on a difference between the first valve leak value and the second valve leak value; andapply the sensor offset correction value in zeroing the flow sensor.