Dynamic temperature reference based on semiconductor light source

The need for fast non-contact temperature measurements, such as with pyrometers and thermal cameras, is great in many industries. Temperature measurement of individual blades when testing turbines, during welding and during machining are just a few examples.

Static calibration despite rapid temperature changes

Calibration of non-contact thermometers is conventionally done under static conditions. The measuring instrument is aimed at a reference source, a black body, with a constant temperature for a long period of time. However, many of today's thermal cameras and pyrometers can make more than 1,000 measurements per second. Verifying that the measuring instrument is making an accurate temperature measurement is not possible with conventional calibration equipment.

Verify correctness

The purpose of the project is to verify that non-contact measuring instruments can measure the correct temperature even when the temperature changes very rapidly. By using a LED or laser light source which in turn is calibrated against a black body, it will be possible to reach the high speeds required.

The intensity can be varied very quickly

Very fast measuring instruments detect radiation within a small wavelength range and then converts the intensity of the radiation into a temperature reading. By generating radiation with a semiconductor light source, such as a LED or laser, the light source can be used to calibrate the measuring instrument instead of using a black body. The light source's intensity is in turn calibrated against a black body to an intensity that corresponds to a certain temperature. The intensity of the LED or laser source can then be varied very quickly, allowing the dynamic response of a pyrometer or thermal camera to be investigated at very high speeds.

Continuation of previous projects

The national laboratory for temperature has focused on the development of dynamic measurements for a long time, among other things by developing a mechanical device that makes it possible to switch between room temperature and the temperature of a black body 1,000 times per second. This project builds on the experiences from that project. Read more about the previous project.