EMISSIVITY MEASUREMENT APPARATUS

The present Setup is designed to measure the emissivity of the test plate. The test plate comprises a mica heater sandwiched between two circular plates. The black plate is identical to the test plate, but its surface is blackened. As all the physical properties, dimensions and temperature are equal; heat losses from both plates will be the same except radiation loss. Hence the input difference will be due to the difference in emissivity. Both plates are supported on individual brackets in an enclosure with one side glass to ensure steady atmospheric conditions. Temperature Sensors are provided to measure the temperature of each plate and surrounding. Electric Supply is given to heaters through separate variacs so that temperatures of both can be kept equal and is measured with Digital Voltmeter and Digital Ammeter.