The influence of object emissivity on radiation temperature measurement: Almost all actual objects existing in nature are not black bodies. The radiation amount of all actual objects depends not only on the wavelength of radiation and the temperature of the object, but also on the types of materials that constitute the object, the preparation method, the thermal process, and the surface state and environmental conditions. Therefore, in order for the law of black body radiation to apply to all practical objects, a proportionality factor related to the properties of the material and the state of the surface must be introduced, namely the emissivity. This coefficient represents how close the thermal radiation of an actual object is to that of a black body, and has a value between zero and a value less than 1. According to the law of radiation, as long as the emissivity of the material is known, the infrared radiation characteristics of any object can be known.
