Intelligent Gas Flow Sensor Probe

An apparatus comprising:

• a sensor probe comprising a heated thermistor and a reference thermistor functionally coupled to a microcontroller, both thermistors having equivalent temperature coefficients;
• the heated thermistor being continuously heated at a constant rate to a temperature elevated above an ambient temperature within the conduit and configured to output to the microcontroller, a real time heated temperature signal responsive to a gas flow within the conduit;
• the reference thermistor configured to output to the microcontroller, a real time ambient temperature signal responsive to an ambient temperature within the conduit;
• the microcontroller comprising executable instructions embodied on a tangible and non-transient computer readable medium 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• locating in microcontroller memory a stored historical reference data value closest to a digital representation of the real time ambient temperature signal;
• comparing a corresponding historical heated temperature data value associated with the located historical reference data value with a digital representation of the real time heated temperature signal;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 of the present gas flow state within the conduit.

An apparatus comprising:

• a sensor probe dimensioned to fit within an aperture formed in a wall of a conduit, the sensor probe comprising a heated thermistor and a reference thermistor functionally coupled to a microcontroller, both heated and reference thermistors having negative temperature coefficients;
• the heated and reference thermistors being installed on opposing surfaces of a printed circuit board, such that a thickness of the printed circuit board provides the reference thermistor with thermal insulation from a heat source associated with the heated thermistor;
• the heated thermistor being continuously heated at a constant rate to a temperature elevated above an ambient temperature within the conduit and configured to output a real time heated temperature signal responsive to a gas flow within the conduit;
• the reference thermistor configured to output a real time ambient temperature signal responsive to an ambient temperature within the conduit;
• the microcontroller comprising executable instructions embodied on a tangible and non-transient computer readable medium 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 reference data value with a digital representation of the real time heated temperature signal;
• determining from the comparison a present gas flow state within the conduit;
• signaling a control circuit functionally coupled to the microcontroller of the present gas flow state within the conduit.