The apparatus consists of blower unit fitted with the test pipe. Nichrome wire heater surrounds the test section. Four Temperature Sensors are embedded on the test section, two placed in the air stream at the entrance and exit of the test section to measure the inlet and outlet air temperature. Test pipe is connected to the delivery side of the blower along with the orifice to measure flow of air through the pipe. Constant heat flux is given to pipe by an electric heater through a variac and measured by Digital Voltmeter and Digital Ammeter.