A METER FOR MEASURING QUANTITIES OF HEAT

A heat quantity meter for measuring the quantity of heat abstracted from a circulating flow of liquid by a consumption unit based upon the indirect measurement of the volume flow rate of the liquid, while maintaining a sub heat flow from and/or to the main heat flow transported by the flow of liquid, the volume flow rate of the flow of liquid being determined on the basis of the flow rate dependant heat transfer in the boundary layer of the flow liquid at the location of the sub heat flow, by determining the temperature differential across the boundary layer and the sub heat flow passing through said boundary layer, comprising a conduit section (26) for the supply flow of liquid (24), possibly a conduit section (27) for the drain flow of liquid (25), a thermal connection (3) to at least one of said conduit sections to obtain the sub heat flow, at least one temperature sensor (22,23) on the supply conduit section or/and the drain conduit section and two additional temperature sensors (20,21) on the thermal connection on either side of the heat resstance thereof to determine the quotient of the temperature differential across the fixed heat resistance of the thermal connection and the temperature differential across the boundary layer. The thermal connection and the measuring bodies of the temperature sensors being of easily heat conducting material are taken up in a housing (30) through thermal insulation means (28,29,37,43) having in its entirety such an implementation that a linearized and reproduceable relation is obtained between the said quotient of temperature differentials and the volume flow rate.