Device for the contactless and non-destructive testing of a surface by measuring its infrared radiation

A device for the contactless and non-destructive testing of a surface by measuring its infrared radiation thereof, comprising:

• one or more electromagnetic radiation sources adapted to emit excitation radiation which can be directed onto a surface to be tested;
• a detector arranged on a detection axis directed towards the surface to be tested;
• a first IR filter medium provided between each radiation source and the surface to be tested;
• at least a second filter medium provided between the first IR filter medium and the surface to be tested;
• and
• a first coolant channel for a cooling fluid circulation created as a space between the first and the second filter medium,
• wherein, in response to excitation radiation impinging onto the surface to be tested, detection radiation is emitted by the surface to be tested and fed to the detector, wherein the coolant channel is connected to a coolant drive for actively exchanging the fluid for the cooling fluid circulation, wherein a first insulation wall and a second insulation wall are provided between the one or more electromagnetic radiation sources and the detector, wherein a space is provided between the first insulation wall and the second insulation wall creating a second coolant channel for a cooling fluid circulation.