Infrared radiation

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About the origin and effect of infrared radiation


How infrared radiation can be used in technology

For the human

this kind of radiation is a directly perceptible small part of the electromagnetic spectrum, as the light visible with the eyes and with the heat receptors of the skin tangible infrared light (heat radiation).

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Infrared radiation

Although  humans cannot see it, but can only perceive it as "heat radiation" on their skin, the infrared radiation is part of the optical radiation.

The  IR radiation is therefore part of the electromagnetic spectrum.

The  main supplier and thus the most important natural source of this heat radiation is the sun with 50% of the solar radiation arriving on the ground.

This  has a decisive influence on the energy balance of the earth and global climate change, because not only the surface of the earth warmed by the sun emits heat radiation again, but also the natural and artificial gases contained in the atmosphere absorb the infrared radiation emitted by the earth. Radiation.

Conversely,  every object that generates or emits heat (i.e. practically everything above absolute zero 0K or -273 ° C) - regardless of whether it is a living or an artificial heat generator - emits IR radiation. 

The  wavelengths that can be measured and the heat emitted depend on the heat of the object in question

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The  IR radiation is a component of the electromagnetic radiation spectrum

However,  the spectral range cannot be clearly defined, since different divisions vary due to specific applications or certain physical phenomena.

A  very common subdivision defines, for example:
● "Near infrared" (NIR) - wavelengths 780 nm to 3 µm
● "Middle infrared" (MIR) - wavelengths 3 µm to 50 µm
● "Far Infrared" (FIR) - wavelengths 50 µm to 1 mm.

Another  classification (according to DIN 5030 Part 2) differentiates the NIR as follows:
● IR-A (780 nm - 1.4 µm) and 
● IR-B (1.4 µ - 3.0 µm). 

The  limit at 3.0 µm is the absorption of IR radiation by water, which increases significantly above this value. 

Therefore,  according to the above The MIR and FIR classifications are combined to form the name IR-C.

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IR radiation in industrial measurement

In  opposite to humans, some animal species in the NIR range can perceive their surroundings via the eyes as well as other sensory organs or can even use this ability for foraging.

Non-contact  measurement of surface temperatures has been technically feasible since around 1960.

At  that time, however, expensive sensors and evaluation technology were a hindrance to widespread use in industrial measurement technology.

Only  new manufacturing technologies and falling costs for production and materials helped this measuring method to make a breakthrough and so today there are various inexpensive handheld measuring devices for non-contact temperature measurement on offer.

These  devices are used wherever conventional contact thermometers cannot be used or can only be used to a limited extent.

Such  measuring devices only passively use the IR radiation from other heat sources, while, in contrast, IR radiation is actively used for moisture measurement using sensors from RGI Industriemessgeräte GmbH.

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Types of radiation

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Gamma radiation

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Infrared radiation

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Neutron radiation

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