Heat meter


A heat meter or flux calorimeter is a device which measures thermal energy provided by a source or delivered to a sink, by measuring the flow rate of the heat transfer fluid and the change in its temperature between the outflow and return legs of the system. It is typically used in industrial plants for measuring boiler output and heat taken by process, and for district heating systems to measure the heat delivered to consumers.
It can be used to measure the heat output of say a heating boiler, or the cooling output from a chiller unit.

Elements

A heat meter consists of
  1. a fluid flow meter - typically a turbine-type flow meter, or alternatively an ultrasonic flow meter;
  2. a means of measuring the temperature between the outflow and the inflow - usually a pair of thermocouples;
  3. a means of integrating the two measurements over a period of time - typically half an hour - and accumulating the total heat transfer in a given period.