A Calibration Resource for non-contact Dynamic Temperature Measurement

The need to be able to calibrate and verify different types of non-contact temperature measurement systems is steadily increasing. In addition to measuring static temperature accurately, there is also an increasing interest in being able to verify that the rapid temperature changes that today's measurement systems can register actually correspond to the real temperature change.

The National Laboratory for Temperature has a number of reference blackbodies that can generate stable temperatures within a large range, from -30 to over 2300 °C. In the project, a piece of equipment was developed which, together with these references, can generate dynamic temperatures that alternate between the desired temperature and room temperature. The system consists of an optical chopper, which is placed between the pyrometer and the black body, and whose rotation speed is controlled by a measuring system. The equipment can automatically sweep through the desired frequency range up to frequencies that correspond to a response time of the pyrometer of 0.5 ms. By saving the measurement data from the pyrometer, it is possible to analyze the information afterwards to see at which chopper frequency the pyrometer can no longer go from room temperature to the temperature of the black body, which gives the response time for the pyrometer.