The apparatus consists of a small test cylinder. The cylinder is heated by a constant temperature water bath, till steady state is reached. During heating, temperature of the cylinder is function of time and hence, heating of cylinder is under unsteady state heat transfer. The temperature of cylinder is measured with the help of temperature sensor inserted in the centre. The hot water bath is provided with a heater and is controlled by digital temperature controller. An agitator is also provided to maintain the constant bath temperature.