Emissivity Measurement Apparatus
The emissivity measurement apparatus is used to measure an object's ability to emit infrared energy. Through measuring emissivity the apparatus determines whether an object can be classified as shiny mirror( having an emissivity value of 0 ) or as black body( having an emissivity value of 1).
The measurement of emissivity is necessitated in several objects. These objects range from insulated windows, solar heat collectors , pyrometers and infrared cameras. Simply put, all objects do have some sort of emissivity. The actual emissivity determination is required so as to ensure the objects are ideal for optimal functional use.
The emissivity measurement apparatus is power efficient, easy to operate and has enhanced safety features for the operator. Furthermore, these are ergonomically designed so as to enable easier handling and faster object changeover times. The apparatus is fit for training laboratories as well as for industrial use. Clients can avail the apparatus as per their requirements at market competitive rate.
The apparatus generally consists of two aluminum plates identical in size and provided with heating coils at the bottom. The aluminum plates are kept in an enclosure to provide undisturbed natural convection surroundings.
The object whose emissivity is to be measured is kept in the aforementioned aluminum plate( test plate) in the enclosure
The heat input to the heater is controlled by dimmer stats and is measured by using an ammeter and a voltmeter.
Various separated wires are connected to the aluminum plates for getting their average surface temperature.
The heater inputs to the aluminum plates are dissipated from the plates through conduction, convection and radiation. Under steady conditions, the heat dissipated by conduction and convection is identical for both the plates
Thermocouples are also kept in the test enclosure for calculating the temperature of the enclosure.
Working Procedure of Emissivity Measurement Apparatus
Give power supply to the apparatus and adjust the reading in the temperature indicator until it is equal to the prevalent room temperature
Choose the ideal range of voltage on voltmeter and ammeter
Gradually increase the power input to the heater of the back plate and also adjust the power input of the test plate to slightly less than that of the back plate
Periodically keep checking the temperatures of the two plates and make necessary adjustments so as to ensure the temperatures of the two plates are identical
After achieving the steady state, record the readings for calculations. The result of these calculations will provide the emissivity score of any object
Precautions to Take While Using Emissivity Measurement Apparatus
Preferably use stabilized A.C single phase power supply.
Ensure that the dimmer stat is at zero before starting.
Use proper voltage range on voltmeters.
Increase power input to the heater gradually.