Infrared Radiation Transparent Film Impact on Thermal Measurement

Measuring surface infrared radiation (IR), thermal infrared detectors can accurately measure surface temperatures with the advantage of non-contact detection. However, IR thermal measurements can only be applied in limited applications due to the limitation that only infrared transparent objects can be placed between the device under test (DUT) and thermal infrared detectors. In this paper, the thermal measurement impact from an IR transparent film has been investigated. The testing setup was built with an IR detector, IR transparent film, and thermocouple instrumented heating element as the device under test. Most of the DUT's metal surface has been prepared with black electric tape, white electric tape, and Kapton thermal tape. Thermocouples were attached to these surfaces as well as areas that were not covered with any material. Thermocouple readings were compared with the results from the IR detectors with and without the IR transparent film. Results show an increasing thermal impact to the measurements as temperatures rose when using the IR transparent film. A minor impact from the various applied surface films was also observed. Correlations between the actual and IR detector measured temperatures when using the IR transparent film were generated, enabling more accurate thermal measurements when using these materials in the future.