Pyrometer

In this PPT u will see the principle of pyrometer,its construction,working,applications etc
all concepts briefly covered

1. MALAVIYA NATIONAL INSTITUTE OF TECHNOLOGY,JAIPUR DEPARTMENT OF CHEMICAL ENGINEERING PRESENTATION | PYROMETER By:- Pushpinder Goyal chemical engineering , MNIT Jaipur 2016uch1640

2. CONTENTS What is pyrometer Working Types of pyrometer Advantages&Disadvantages Referances

3. A pyrometer is a type of remote-sensing thermometer used to measure the temperature of a surface. Various forms of pyrometers have historically existed. In the modern usage, it is a device that from a distance determines the temperature of a surface from the spectrum of the thermal radiation it emits, a process known as pyrometry and sometimes radiometry. Pyrometer a device capable of measuring the temperature of an object by its incandescence, visible light emitted by a body which is at least red-hot. Modern pyrometers or infrared thermometers also measure the temperature of cooler objects, down to room temperature, by detecting their infrared radiation flux. WHAT IS PYROMETER

4. A pyrometer is typically made up of an optical system and a detector. The optical system (a lens) is used to focus the infrared (IR) energy naturally emitted by an object onto a sensor or detector. This sensor is responsive to the infrared radiation and hence transforms IR energy into electrical energy. The electrical output signal of the detector can be displayed in terms of temperature. To do this, standard ambient temperature need to be considered. Emittivity of an object plays a significant role in conversion of the electrical signal into a correct temperature signal.  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 σ, called the Stefan-Boltzmann constant and the emissivity ε of the object. WORKING

5. OPTICAL PYROMETER RADIATION PYROMETER TYPES OF PYROMETER

6. In an optical pyrometer, a brightness comparison is made to measure the temperature. As a measure of the reference temperature, a color change with the growth in temperature is taken. The device compares the brightness produced by the radiation of the object whose temperature is to be measured, with that of a reference temperature. The reference temperature is produced by a lamp whose brightness can be adjusted till its intensity becomes equal to the brightness of the source object. For an object, its light intensity always depends on the temperature of the object, whatever may be its wavelength. After adjusting the temperature, the current passing through it is measured using a multimeter , as its value will be proportional to the temperature of the source when calibrated OPTICAL PYROMETER

7. The main theory behind a radiation pyrometer is that the 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 summarized into two: 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 heat radiated from the hot source is measured at a given wavelength. RADIATION PYROMETER

8. ADVANTAGES 1.Simple assembling 2. Provides a very high accuracy with +/-5 degree Celsius 3.  no need of any direct body contact 4.  The device can  measure very high temperatures 5. It can also be used to see the heat produced by the object/source DISADVANTAGES 1.Not useful for obtaining continuous values of temperatures 2 Only useful for measuring very high temprature 3. Higher cost as compared to conventional thermocouples 4. Advanced radiation thermometers involve extra complicated design and optics. ADVANTAGES&DISADVANTAGES

9. In the blast furnace & metallurgical furnace To measure the steam temperature To measure the moving objects The application is used in smelter industry, over the bath pyrometer, steam boiler, hot air balloons and gas turbine engine. for measuring the temperature through the Tuyere APPLICATIONS

10. REFERANCES 1.http://www.instrumentationtoday.com/optical-pyrometer/2011/08/ 2.http://www.instrumentationtoday.com/radiation-pyrometer/2011/08/ 3.http://automationwiki.com/index.php/Pyrometers https://en.wikipedia.org/wiki/Pyrometer 4. Michalski et al., “Temperature Measurement, Second Edition .(Wiley, 2001), pp. 403-404. 5.http://www.omega.com/literature/transactions/volume1/thermometers1.html