Influence of ambient conditions on the thermometer
The environmental conditions of the infrared thermometer have a great influence on the measurement results, which should be considered and properly resolved, otherwise it will affect the measurement accuracy and even cause damage. When the ambient temperature is high and there is dust, smoke or steam, accessories such as water cooling jackets and air purgers provided by appropriate manufacturers can be selected to effectively solve the environmental impact and protect the thermometer to achieve accurate temperature measurement. When the surrounding environment greatly affects the measured energy signal, a two-color thermometer can be selected to achieve accurate temperature measurement. In applications with sealed or hazardous materials (e.g. containers, vacuum equipment such as vacuum furnaces), the pyrometer looks through a window. The window material must be transparent and transparent to the operating wavelength range of the pyrometer being used. The window of a single-color thermometer needs to keep the entire light passage unobstructed, and keep the window clean; the two-color thermometer does not have high requirements for the cleanliness of the window, as long as the window is not covered by the metal coating.
Determining the emissivity of the object under test
Emissivity indicates the closeness of the thermal radiation of the actual object to the black body radiation. According to the radiation law, as long as the emissivity of the material is known, the infrared radiation characteristics of any object can be known. Therefore, the influence of different objects on the measured temperature caused by different emissivity should be compensated according to the set emissivity. The main factors affecting emissivity are: material type, surface roughness, surface temperature and material thickness. For metal materials, the surface state has a great influence on the emissivity. Generally, the emissivity of the rough surface and the oxidized surface is several times that of the polished surface; for non-metallic materials, the emissivity values are relatively high. Generally between 0185 and 0195, and has little relationship with the surface state. For objects with unknown emissivity, the emissivity of the object can be measured experimentally. For the two-color infrared thermometer, it can be seen from the formula (6): its temperature value is determined by the ratio of the radiation energy in two independent wavelength bands, and its measurement result has nothing to do with the emissivity of the object, and is affected by the surrounding environment It is also relatively small and has strong anti-interference ability.
