Emmissivity Measurement Apparatus

All substance emit thermal radiation at all temperatures and also absorbs all or part of radiation coming from surrounding. The set up is designed to measure emmissivity of given material. It consists of set of two identical circular aluminum plates with mica heater sandwiched in between. Test Plate and Black Plate , both plates are housed in a enclosure to ensure steady atmospheric conditions. A Perspex window is provided to visulise the arrangement. Input to heater can be varied by dimmer stat and measure by help of Digital Voltmeter an Ammeter. Thermocouples are provided to measure the temperatures of these plates. By knowing the heat input and temperatures, one can calculate Emmissivity of non black surface and study the variation of emmissivity of test plate with respect to absolute temperature.

Specifications:

• Test Plate & Reference plate - 160 mm dia.
• Enclosure to house both plates.
• Heater - Nichrome wire heater - 2 No.s

Instrumentation & Controls :

• Digital Voltmeter - 0 - 199.9 Volts.
• Digital Ammeter - 0 - 1.999 Amp.
• Multy channel Digital Temperature Indicator.
• Heater Control - 2 No.

Service Required :

• 230 V.A.C. stabilized supply with earthing.
• Floor space - 1.5 m X 1.5m at working height.