Abstract: The method and apparatus herein described relate to the indirect measuring of thermal energy supplied to a number of user stations, for instance to all the apartments of a single building or to many buildings or the like. A temperature sensor with a voltage frequency converter provides an electric signal with a frequency which varies according to the temperature of the thermal carrier fluid. An electronic circuit processes the temperature signal through a variable multiplier which is set by respective multiplexed heat transfer ratings of the corresponding stations to produce a series of impulse trains corresponding to thermal energy consumed by the corresponding stations. Multiplexed counting devices, controlled by demand signals corresponding to fluid flow in the respective stations, receive the respective pulse trains to produce readings of the thermal energy consumed by the corresponding stations.