The transmission coefficient describes the ability of a material/body to transmit infrared radiation. It depends on the thickness and type of material. The size of the transmittance is specified with a value between 0 and 1.
Other parameters also play a role in the degree of transmission of the solid:
– Thickness of the material
– Surface properties
– Temperature of the material
– Angle of incidence of the radiation

In the infrared range, most measuring bodies have no transmission.

In practice, the transmittance setting is required to compensate for the attenuation of protective lenses/additional lenses, e.g. made of IR-permeable plastic polymer film.

If there is no function for setting the transmittance, the attenuation of the lens can also be set and compensated for via the emissivity setting.