This article provides answers to the following questions, among others:

  • How do IR thermometers (pyrometers) work?
  • What are the advantages of pyrometers?

The thermometers presented in the previous articles must directly touch the object from which the temperature is to be determined. This can be a disadvantage in many cases, for example with very hot materials such as metal melts or corrosive liquids. In such cases non-contact measuring methods are used.

The so-called pyrometer (IR thermometer) detects the thermal radiation (infrared radiation) from objects, which each body emits due to its temperature (see article Black-body radiation). The radiation spectrum recorded by the measuring device thus allows conclusions to be drawn about the temperature of the objects. With the help of such a radiation measuring device, the object to be measured no longer has to be touched directly in order to measure the temperature.

Infrared thermometer (Pyrometer)
Figure: Infrared thermometer (Pyrometer)

Pyrometers (infrared thermometers) use the heat radiation of objects invisible to the human eye to determine the temperature!

Infrared thermometers are often equipped with a laser. However, this laser has only a targeting function. In this way, it is easier to determine the exact location from which the temperature is measured.