Calorimeter

A calorimeter for the measurement of a quantity of heat given up by a fluidic medium in at least one heat exchanger, with an impellerless flow velocity measuring device as well as temperature sensors for determining the forward flow-return flow temperature difference, including a multiplier for forming the product from the flow velocity and the forward flow-return flow temperature difference; and also a quantizer for the formation of a pulse train having a frequency which is proportional to the product, as well as a cumulative counting device for the pulses of the pulse train connected to the output thereof. The flow velocity measuring device is activated only at predetermined points in time or moments, whereby the frequency of these measuring moments is determined approximately proportional to an auxiliary variable which represents a measure for the importance of a possible change in a parameter determining the heating quantities on the measured result, and in which a second multiplier is connected ahead of the quantizer which the output signal of the first multiplier is multiplied with a value proportional to the timewise interval between two measurement switching moments.