EMISSIVITY MEASUREMENT APPARATUS

The apparatus consists of a test plate and a comparator. A black plate is used as a comparator for test plate.When all the physical. dimensions and the temperatures are equal, heat losses from both plates will also be the same, except radiation losses. Hence the input difference will be due to difference in emissive. Both the plates are kept in a panel enclose with perplex front and are given inputs through separate dimmerstats so that temperatures of both can be kept equal.Thus emissivity can determine over a wide range of temperatures.