Patent ID: 7775706

Claim:
A heat meter for measuring heat energy transferred by fluid flowing through a heat exchanger, the heat meter comprising: a fluid flow meter operable to provide a flow signal responsive to a rate at which the fluid flows through the heat exchanger; an inlet temperature sensor operable to provide an inlet temperature signal representative of a temperature of the fluid flowing into the heat exchanger; an outlet temperature sensor operable to provide an outlet temperature signal representative of a temperature of the fluid flowing out of the heat exchanger; a specific heat sensor comprising circuitry operable to measure a ratio between energy supplied to a thermoelectric specific heat sensing element having first and second surfaces in thermal contact with the fluid and an associated change of temperature of the element and to generate therefrom a specific heat signal, wherein the specific heat sensor circuitry is operable to measure a temperature difference between the first and second surfaces of the thermoelectric sensing element responsive to a selected amount of energy being supplied to the thermoelectric element; and signal processing circuitry operable to combine the flow signal, the inlet temperature signal, the outlet temperature signal and the specific heat signal to provide an output representative of the heat energy transferred by the fluid flowing through the heat exchanger.