Patent ID: 8504318

Claim:
A system for determining a flow rate of a fluid, comprising: at least one conduit defining a flow path along which the fluid flows; at least one thermal sensor that generates a thermal sensor signal, which is proportional to a mass flow rate of the fluid; at least one pressure sensor that generates a pressure sensor signal, which indicates the pressure of the fluid; one or more electronics that: generate a thermal sensor based mass flow rate for the fluid, where the thermal sensor based mass flow rate is determined at least in part from the thermal sensor signal; generate a pressure sensor based mass flow rate for the fluid, wherein the pressure sensor based mass flow rate is determined at least in part from the pressure sensor signal; generate at least one calibration factor using the thermal sensor based mass flow rate and the pressure sensor based mass flow rate; generate a calibrated pressure sensor based mass flow rate by using the at least one calibration factor to modify the pressure sensor based mass flow rate; generate a calibrated thermal sensor based mass flow rate by using the at least one calibration factor to modify the thermal sensor based mass flow rate; determine whether operating conditions are substantially stable; output the calibrated thermal sensor based mass flow rate in response to a determination that the operating conditions are substantially stable; and output the calibrated pressure sensor based mass flow rate in response to a determination that the operating conditions are not substantially stable.