An isothermal micro-calorimeter

A calorimeter is described which, although nearly isothermal and independent of the specific heats of the materials employed, can still be used over a wide range of temperatures and makes use of a bank of thermocouples to measure the heat evolved. An attempt is made to obtain the maximum theoretical sensitivity by making most of the heat produced pass down the thermocouples. The high rate of heat transfer down the thermocouple wires has made it possible to pass up to 15 ml./min of air through the calorimeter without affecting the sensitivity.