This document discusses pyrometers, which are devices used to measure temperature without physical contact by measuring the electromagnetic radiation emitted by hot bodies. There are two main types of pyrometers: radiation pyrometers and optical pyrometers. Radiation pyrometers use an optical system including a lens, mirror, and adjustable eyepiece to collect the heat energy emitted by a hot body and focus it onto a detector, which converts it into an electrical signal and temperature display. Radiation pyrometers are able to measure high temperatures without contact and provide a fast response.

1. Radiation
Pyrometers
By: Niraj Trivedi
120200117124

2. Pyrometers
Pyrometry is a technique for measuring
temperature without physical contact. It depends
upon the relationship between the temperature of
hot body and eletronicmagnetic radiation emitted
by the body.
It is a technique for determining a body’s
temperature by measuring its eletronicmagnetic
radiation .
‘ Pyro’ is the ‘Greek’ word which means fire.

3. Two types of pyrometers used in industries :
Radiation Pyrometers
Optical Pyrometers

4.  A pyrometer has an optical system and detector.
The optical system focuses the thermal
radiation onto the detector. The output signal of
the detector(Temperature T) is related to
the thermal radiation or irradiance j* of the target
object through the Stefan–Boltzmann law,
the constant of proportionality, called the Stefan-
Boltzmann constant and the emissivity ε of the
object.

5. Black Body
Spectrum

6. The radiation pyrometer has an 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 eye piece arrangement. The detector
may either be a thermister or photomultiplier tubes. Though
the latter is known for faster detection of fast moving
objects, the former may be used for small scale applications.
Thus, the heat energy is converted to its corresponding
electrical signal by the detector and is sent to the output
temperature display device.

8. ABILITY TO MEASURE HIGH TEMP
NO NEED FOR CONTACT
FAST RESPONSE SPEED
HIGH O/P
MODERATE COST

9.  Emissivity errors are introduced
 Errors due to the absorption of radiation by carbon dioxide,
water or other apparently transparent gases.

10.  They are used for temperatures above the practical
operating range of thermocouples.
 They can be used in the environments which
contaminate or limit the life of thermocouple.
Used for moving targets.
 They are used for measurement of average
temperature of large surface areas.
 They are used for the targets which would be damaged
by contact with primary elements like thermocouples and
resistance thermometers.

12. Thank
you