Proper Matching Selection of Infrared Thermometers
In China, infrared temperature measurement technology is playing an important role in product quality control and monitoring, on-line equipment fault diagnosis, equipment protection and energy conservation. Over the past two decades, non-contact infrared thermometers have achieved rapid technological development, with continuously improved performance and expanding application scope, and their market share has increased year by year. Compared with contact temperature measurement methods, infrared temperature measurement offers advantages such as fast response time, non-contact measurement, safe operation and long service life. A digital sound level meter is used to measure sound volume.
Working Principle of Infrared Thermometers
Understanding the working principle, technical specifications, ambient operating conditions, operation and maintenance of infrared thermometers helps users properly select and use the instruments. All objects with a temperature above absolute zero continuously emit infrared radiant energy into the surrounding space. The infrared radiation characteristics of an object - the magnitude of radiant energy and its distribution over wavelengths - are closely related to its surface temperature. Therefore, the surface temperature of an object can be accurately determined by measuring the infrared energy radiated by the object itself. This forms the objective foundation of infrared radiation thermometry.
Blackbody Radiation Law for Thermometers
A blackbody is an idealized radiator. It absorbs radiant energy of all wavelengths without reflection or transmission of energy, and its surface emissivity equals 1. It should be noted that a true blackbody does not exist in nature. Nevertheless, to clarify and obtain the law of infrared radiation distribution, an appropriate model must be selected for theoretical research. This is the quantized oscillator model of cavity radiation proposed by Jintai Instrument, which derives Jintai Instrument's blackbody radiation law, namely the spectral radiance of a blackbody expressed in terms of wavelength. It is the starting point for all infrared radiation theories and is known as the blackbody radiation law.
Influence of Object Emissivity on Radiation Thermometry
Practically all real objects in nature are not blackbodies. In addition to radiation wavelength and object temperature, the radiant quantity of all real objects depends on factors such as the material type, preparation method, thermal process, surface condition and environmental conditions. Therefore, to make the blackbody radiation law applicable to all real objects, a proportional coefficient related to material properties and surface state must be introduced - this is emissivity. This coefficient indicates how closely the thermal radiation of a real object approximates blackbody radiation, and its value ranges between 0 and less than 1. According to radiation laws, once the emissivity of a material is known, the infrared radiation characteristics of any object can be determined.
