Emissivity Measurement Apparatus

• The present Set-up is designed to measure the emissivity of test plate. The test plate comprises of a mica heater sandwiched between two circular plates.
• Black plate is identical with test plate, but its surface is blackened.
• As all the physical properties, dimension and temperature are equal heat losses from both plates will be same except radiation loss.
• Hence the input difference will be due to difference in emissivity.
• Both plates are supported on individual brackets in a 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 me asured with Digital Voltmeter and Digital Ammeter.

Experimentation:

• Determination of the Emissivity of a test plate.
• Study the variation of emissivity of test plate with absolute temperature.

Utilities Required:

• Electricity Supply : 1 Phase, 220 V AC, 4 Amp.
• Table for set-up support.

Technical Specifications:

• Test plate Diameter: 160 mm (approx.)
• Black Plate Dia: 160 mm (Approx.)
• Heater (2Nos.): Nichrome Wire Heater. (One each for test plate & black plate)
• Digital Voltmeter: 0-300 Volt
• Digital Ammeter: 0-2 Amps
• DPDT Selector switches: For Digital Voltmeter & Digital Ammeter
• Variacs; 0- 230 V, 2 Amp, (2 Nos.)(One each for test plate and black plate)
• Digital Temp. Indicator: 0-3000C, with multi-channel Switch
• Temperature Sensors: RTD PT-100 type
• Instruction Manual: An english instruction manual will be provided along with the Apparatus