The Model 212 Heat Calculator is designed to measure the energy consumed in both heating and cooling (air conditioning) systems. The instrument is normally supplied complete with temperature probes and power supply, and will interface to a wide variety of flowmeters, including positive displacement and inferential water meters, magnetic flowmeters with pulse outputs, turbine flowmeters & paddlewheel flowmeters. The Model 212 measures the temperature in the feed and return flow lines and uses this information to calculate the density and enthalpy of water. By also measuring the volume of water flowing in the system, the Model 212 will then determine the energy used.