Factory Applications of Infrared Thermometers
Temperature, pressure, current, and voltage are all basic physical quantities that people are familiar with. In the industrial field, it has a great influence on the quality of products and the control of the whole process. Among these basic physical quantities, the measurement and calibration of temperature are much more difficult. This is because the influence of the "adiabatic" and "heat transfer" of the temperature system itself is very complex, which results in a large volume of the temperature measurement calibration system, a long stabilization time, and difficulty in improving the accuracy. It is not like the pressure system, as long as the leakage of the pressure transmission pipeline can ensure that the internal and external pressures do not affect each other, it is easy to achieve rapid pressure transmission, the stabilization time is only a few milliseconds, and the measurement accuracy can easily reach a few ten thousandths or more.
Considering a temperature measurement system with high accuracy and high stability, it is impossible to guarantee that it is "adiabatic", that is, to completely prevent heat transfer. People usually make a large enough volume reach thermal equilibrium, and consider that the temperature field gradient of a small volume at its inner mass center is sufficiently balanced, which is one of the important reasons why the temperature calibration source is bulky. In addition, the heat transfer of a temperature system is also very complex, which is often completed by heat conduction, convection and radiation. It is conceivable that it is almost impossible to suddenly make the temperature abruptly and reach thermal equilibrium. This is the conventional temperature calibration source. To ensure a certain uniformity of the temperature field, the volume of the device is large, and the heating and cooling time is long, which causes the inspection, maintenance and calibration of the temperature measurement system in the industrial field, which is time-consuming, labor-intensive and expensive, and affects the reliability of the system due to multiple disassembly and assembly of the temperature probe. .
The industry hopes to have a small and lightweight portable temperature correction source (thermostatic bath) like a pressure calibrator. However, this small and portable temperature calibrator must overcome the poor uniformity of the temperature field and the The disadvantage of poor stability is that in order to stabilize the temperature rise and fall in a short period of time, there must be close cooperation between heating and cooling, which can reduce the heating and cooling time. Due to the uniformity of the temperature field, a portable temperature calibrator with ultra-small volume and a certain accuracy, rapid temperature rise and fall, is a field application instrument that has been explored and developed for many years in the field of temperature measurement technology.
Infrared detection technology is a key promotion project of national scientific and technological achievements in the "Ninth Five-Year Plan". Infrared detection is a high-tech detection technology of on-line monitoring (without power interruption), which integrates photoelectric imaging technology, computer technology and image processing technology. The infrared rays (infrared radiation) emitted are displayed on the fluorescent screen, so as to accurately judge the temperature distribution of the surface of the object, which has the advantages of being accurate, real-time and fast. Due to the movement of its own molecules, any object continuously radiates infrared heat energy outward, thereby forming a certain temperature field on the surface of the object, commonly known as "thermal image". The infrared diagnostic technology measures the temperature of the equipment surface and the distribution of the temperature field by absorbing this infrared radiation energy, thereby judging the heating condition of the equipment. There are many test equipments that apply infrared diagnostic technology, such as infrared thermometers, infrared thermal TVs, infrared thermal imaging cameras and so on. Equipment such as infrared thermal TV and infrared thermal imager use thermal imaging technology to convert this invisible "thermal image" into a visible light image, so that the test effect is intuitive and the sensitivity is high. It can detect the subtle thermal state changes of the equipment and accurately reflect The internal and external heating conditions of the equipment have high reliability and are very effective in discovering equipment hidden dangers.
Infrared diagnostic technology can reliably predict the early fault defects and insulation performance of electrical equipment, and improve the preventive test maintenance of traditional electrical equipment (preventive test is the standard introduced in the former Soviet Union in the 1950s) to predictive state maintenance, which is also a modern electric equipment. The direction of enterprise development. In particular, the development of large units and ultra-high voltage has put forward higher and higher requirements for the reliable operation of the power system, which is related to the stability of the power grid. With the continuous development, maturity and perfection of modern science and technology, the use of infrared state monitoring and diagnosis technology has the characteristics of long-distance, non-contact, non-sampling, and non-disintegration, as well as being accurate, fast, and intuitive, and can monitor and diagnose electrical equipment online in real time. Most faults (can cover the detection of various faults of almost all electrical equipment). It is highly valued by the electric power industry at home and abroad (an advanced condition-based maintenance system widely used in the late 1970s abroad) and has developed rapidly. The application of infrared detection technology is of great significance to improve the reliability and effectiveness of electrical equipment, improve operational economic benefits, and reduce maintenance costs. It is a good method widely popularized in the field of predictive maintenance, and it can bring the maintenance level and the health level of the equipment to a higher level. [2]
