Thermal mass flowmeter

Claim 1

INSTRUMENTATION OF SENSING MASS RATE OF FLUID FLOW WITHIN A FLUID CONDUIT COMPRISING: IMPEDANCE MEANS ADAPTED TO BE DISPOSED WITHIN THE FLUID CONDUIT, THE IMPEDANCE MEANS HAVING A NEGATIVE RESISTANCE CHARACTERISTIC WITH RESPECT TO TEMPERATURE SO THAT THE IMPEDANCE OF THE IMPEDANCE MEANS INCREASES WITH DECREASES IN TEMPERATURE THEREOF AND VICE VERSA, MEANS FOR CONNECTING THE IMPEDANCE MEANS TO A SOURCE OF ELECTRICAL ENERGY SO THAT CURRENT IS PASSED THROUGH THE IMPEDANCE MEANS TO CAUSE HEATING THEREOF ABOVE THE TEMPERATURE OF FLUID WITHIN THE FLUID CONDUIT SO THAT THE TEMPERATURE OF THE IMPEDANCE MEANS AND THUS THE VOLTAGE ACROSS THE IMPEDANCE MEANS VARIES WITH CHANGES IN FLUID MASS FLOW IN THE FLUID CONDUIT, THE VOLTAGE ACROSS THE IMPEDANCE MEANS BEING A NONLINEAR VOLTAGE WITH RESPECT TO FLUID MASS FLOW, A LINEARIZING FUNCTION GENERATOR CONNECTED TO THE IMPEDANCE MEANS SO THAT THE NON-LINEAR VOLTAGE ACROSS THE IMPEDANCE MEANS IS MADE SUBSTANTIALLY LINEAR WITH RESPECT TO FLUID MASS FLOW, THE LINEARIZING FUNCTION GENERATOR HAVING FIRST AND SECOND ARMS, ONE OF THE ARMS HAVING A RESISTOR ELEMENT CONNECTED THEREIN AND DISPOSED WITHIN THE FLUID CONDUIT, THE RESISTOR ELEMENT HAVING A NEGATIVE RESISTANCE CHARACTERISTIC WITH RESPECT TO TEMPERATURE SO THAT THE RESISTOR ELEMENT COMPENSATES THE LINEARIZING FUNCTION GENERATOR SUCH THAT THE OUTPUT OF THE LINEARIZING FUNCTION GENERATOR IS SUBSTANTIALLY INDEPENDENT OF THE TEMPERATURE OF THE FLUID IN THE FLUD CONDUIT.