Emissivity is the ratio of the radiated energy of an actual object to a black body of the same temperature under the same conditions. The so-called same conditions refer to the same geometric conditions (emitting radiation area, solid angle size and direction for measuring radiation power) and spectral conditions (spectral range for measuring radiation flux). Since emissivity is related to measurement conditions, there are several definitions of emissivity.

For a black body, all emissivities are equal to 1, while for real objects, the values of various emissivities are less than 1. The emissivity we are talking about so far is the average emissivity.

The emissivity correction method of the infrared thermometer is to adjust the amplification factor of the amplifier according to the emissivity of different objects, so that the radiation of an actual object with a certain temperature produces a signal in the system that is the same as that produced by a black body with the same temperature. The signals are the same. For example, if the emissivity of a certain object is {{0}}.8, then the magnification of the amplifier needs to be increased to 1/0.8=1.25 times. However, in industrial sites, it is generally difficult to determine the target emissivity parameters due to the different materials, shapes and surface conditions of the measurement targets. There are also measurement errors caused by other factors that will cause the difference between the measured value and the true value. The introduction of emissivity parameter adjustment can solve this problem well without affecting the measurement linearity. You can adjust it based on experience temperature or process temperature according to the following steps:

For example: the measuring range of the thermometer is: 500-1400 degree

The real temperature is 1200 degree , the measured temperature is 1150 degree ,

(1150-500)÷(1200-500)=0.928≈0.93