Let’s get to our main question, How does the infrared thermometer work?. The infrared
thermometer, also known as the pyrometer works on the simple principle of detecting the
infrared waves from the object and changing the signalto electrical units. It contains an infrared
detector, which detects the infrared waves, emittedby the object whose temperature is being
measured. But, these detected signals need to be convertedto a number that a human can
understand. So simple energy conversion happens, inwhich infrared signal detected is
converted to electrical signals.
Let’s see the whole process in little detail. So firstthe thermometer is brought near to the
surface of the object whose temperature is being measured.The infrared rays are transmitted
by the object, which is detected by the detector inthe thermometer. The detector is known as a
thermopile. Thermopile is nothing but some thermocoupleconnected in series or parallel. When
the infrared rays come in contact with the thermopilesurface, they get absorbed and converted
into heat. This heat is converted into electricalvoltage output by thermocouples. This voltage
output is used by the detector to measure temperature,and this temperature is displayed on the
screen, in the thermometer. This whole process happenswhen a person pushes the trigger of
the gun. This may sound complicated, but it only takesa few seconds to measure the
temperature of the gun.
This is the basic process that occurs in every infraredthermometer available in the market. The
only difference in the pyrometer of different companiesin the way they compare the
temperatures. There must be a reference point throughwhich other things are measured.
Everything we measure is in terms of some ground pointor reference point. So a reference is
needed for measuring temperature also. So one typeof thermometer uses a predefined
wavelength inbuilt in it to measure temperature. Itcompares the wavelength of the object with
the reference wavelength already present and thusmeasures the temperature. Another type of
thermometer has an internal heat source inbuilt, andthey compare the temperature of both to
find the temperature of the object whose temperatureis being measured. The difference is just
in the way they compare and find the temperature;the basic mechanism of detecting the
infrared rays is similar in all pyrometers.