A calorimetric method for measurement of total loss in a power transformer

The traditional drop calorimeter, used to determine the specific heat of materials, is modified to derive a power dissipation calorimeter suited for measuring the total loss in devices such as transformers. The concept of the drop calorimeter is described. Modifications required to measure the total loss in a device such as a transformer are presented. A discussion is given of methods to compensate for heat losses to the environment surrounding the calorimeter, the thermal mass of the transformer whose power dissipation is being measured, and heat leaks through the transformer lead wires. A detailed description of the calorimeter used to determine the power dissipation of a multi-winding printed-wiring transformer is given. This includes details of the test set-up, system calibration, test procedure, and data reduction methods