Emissivity is the ratio of the energy radiated from the exterior of the policy to the radiant energy of the black body at the same temperature. It is determined by the material of the object itself. For example, the emissivity of plastic is 0.95, the emissivity of ice is 0.98, and the emissivity of basalt is 0.7 and many more. In this case, in order to obtain the correct temperature measurement result, before measuring the temperature with an infrared thermometer, we should set the correct emissivity parameter according to the raw materials of the measured policy. How to set the emissivity parameter of the infrared thermometer? There are three main approaches.

First, coloring method. This method is mainly to paint the exterior of the policy in black, and set the emissivity of the thermometer to the emissivity of black paint (or black tape) to 0.97 (0.93), and then use the infrared thermometer to measure the temperature T1 of the black part. Then use an infrared thermometer to measure the external temperature T2 of the part close to the black part, and adjust the emissivity value of the infrared thermometer to make T2 close to T1. The emissivity value obtained at this moment is the emissivity of the measured target.

Second, the comparison method. Find a contact temperature probe, measure the temperature on the surface of the measured policy, and after the temperature reaches a stable level, adjust the emissivity of the infrared thermometer so that the temperature value measured by the infrared thermometer and the temperature measured by the contact temperature probe The temperature display is consistent, and the emissivity at this moment is the emissivity of the measured target.

Third, look-up table method. According to the emissivity table provided in the operation manual or related documents, according to the raw materials of the measured policy, find the corresponding emissivity value and set it.