Quick Answer: Emissivity Measurement Apparatus compares a test plate with a black plate, both 160 mm dia. aluminum plates with mica heaters inside, to find the emissivity of the test surface. Separate dimmers keep both plates at equal temperature, and a multichannel digital indicator reads the temperatures.
Last updated: October 2026
Key Features
Test plate and black comparator plate, 160 mm dia. aluminum
Mica heater inside each plate
Voltmeter and ammeter switched between both heaters by a selector switch
Separate dimmers for each plate
Panel enclosure with Perspex front
Technical manual supplied
Technical Specifications
Specification
Value
Plates
Test plate and black plate, 160 mm dia. aluminum, mica heater inside
Input measurement
Voltmeter and ammeter with selector switch
Controls
Separate dimmers for both plates
Temperature
Multichannel digital temperature indicator
Space
1.5 m x 1 m at working height
Supply
230 V, 15 A, AC with earthing connection
About This Product
With equal dimensions and temperatures, both plates lose the same heat except by radiation, so the difference in heater input is due to the difference in emissivity. Adjusting the two dimmerstats to hold the plates at equal temperature lets students determine emissivity over a wide range of temperatures. For a HEAT TRANSFER LAB, it needs a 230 V, 15 A AC supply with earthing and 1.5 m x 1 m of space at working height.
Frequently Asked Questions
Q1. Why is a black plate used? The black plate is the comparator. When both plates have equal dimensions and temperatures, heat losses are the same except radiation losses, so the input difference is due to the difference in emissivity.
Q2. Can emissivity be measured at different temperatures? Yes. Separate dimmerstats keep both plates at equal temperature, so emissivity can be determined over a wide range of temperatures.
Lab Equipments Ambala supplies institutions and distributors in Cameroon, Mozambique and Papua New Guinea, as part of its export work to 80+ countries.
