2. Government Engineering College Valsad

3. Submitted To Prof. Y.J.Morabiya CHEMICAL DEPARTMENT For the Subject Instrumentation and Process control

4. Prepared By Shukla Meghna S. Enrollment No. = 130 190 105 102 On behalf of Div = 2 Chem. 3 rd year, 5 th sem

5. TOPIC

6. An instrument which measures the temperature of a hot object by focusing the thermal radiation emitted by the object and making some observation on it, optical, and ratio pyrometers. Also known as “noncontact thermometer; radiant energy thermometer; radiation thermometer”.

7. Temperature is measured through the naturally emitted heat radiation by the body. This heat is known to be a function of its temperature. According to the application of the device, the way in which the heat is measured can be into two:

8. 1.Total radiation pyrometer In this method, the total heat emitted from the hot source is measured at all wavelengths. 2. Selective radiation pyrometer In this method, the total heat emitted from the hot source is measured at given wavelengths.

9. As shown in the figure,the radiation has optical system, including a lens, a mirror and an adjustable eye piece. The heat energy emitted from the hot body is passed on to the optical lens, which collects it and is focused on to the detector with the help of the mirror and the and eye piece arrangement. The detector may either be a thermistor or photomultiplier tubes. Though the later is known for faster detection of fast moving objects, the heat energy is converted to its corresponding electrial signal by the detector and is sent to the output temperature display device.

11. The device can be used to measure high temperatures without direct contact with the hot source (Molten metal). The biggest advantage is that the optical lens can be adjusted to measure temperature of objects that are even 1/15 inch in diameter and that too kept at along s = distance from the measuring device.

12. The sight path of the device is maintained by the construction of the instrument components, such as the lens and curved mirrors.

13. Disadvantages Non linear scale Emmisivity of target affect measurement Errors due to interleaving media

14. Thank you