Patent ID: 8594953
Filing Date: 2013-11-26
Classification: G01F

Abstract:
1. A method comprising: providing a sensor probe comprising a heated thermistor and a reference thermistor functionally coupled to a microcontroller, both heated and reference thermistors having equivalent temperature coefficients; outputting from the heated thermistor a real time heated temperature signal responsive to a gas flow within the conduit to the microcontroller; outputting from the reference thermistor a real time ambient temperature signal responsive to an ambient temperature within the conduit to the microcontroller; providing the microcontroller with tangible and non-transient executable instructions for: locating in microcontroller memory a stored historical reference data value closest to a digital representation of the real time ambient temperature signal; comparing a corresponding historical heated temperature data value associated with the located historical reference data value with a digital representation of the real time heated temperature signal; determining a present gas flow state within the conduit from the comparison; signaling a control circuit functionally coupled to the microcontroller the determined present gas flow state within the conduit.