The principle and characteristic of infrared temperature measurement technology

Infrared is infrared radiation, infrared or infrared light for short, it is the solar spectrum of red light is not visible light, its wavelength range is quite wide, 0.75-1000m. The thermal effect of sunlight increases gradually from violet to red light, and the infrared light has the largest thermal effect. In addition to solar radiation infrared light, any object in nature, as long as it has a certain temperature, can radiate infrared light.

2. Fundamental principle of infrared temperature measurement

According to Boltzmann's law, the higher the temperature of an object, the greater the radiated power. As long as the object's temperature and its specific emissivity are known, the radiated power of the object can be calculated. On the contrary, if the radiated power emitted by the object is measured, its temperature can be determined, which is the principle of infrared temperature measurement.

The principle of infrared temperature measuring device is shown in Figure 2-3. It is composed of optical system, modulation plate, infrared detection element, amplifier and display.

3. Characteristics of infrared temperature measurement

(1) Non-contact measurement. It does not affect the temperature distribution of the measured target and can be used to measure the temperature of distant, charged and untouchable targets.

(2) Quick response. Infrared light travels at the speed of light. The response time of Infrared Thermometer mainly depends on electronic circuits and display devices. It is generally a few tenths of a second, so it can be used to measure the temperature of high-speed moving objects.

(3) High sensitivity. Can distinguish the minute temperature difference of the target.

(4) Wide Range of temperature measurement. It can measure the temperature range from -10 ℃ to 1300℃.

4. Thermal Imaging Instrument

Thermal imager uses Infrared Imaging technology, which uses an Infrared sensor to collect the Infrared radiation signal of the object under test. After the signal is amplified and processed, the visible image of the temperature distribution graph (two-dimensional temperature field) of the object under test is formed on the display.

5. Application of infrared temperature measurement and thermal imaging technology in diagnosis

Infrared measuring temperature imaging technology in equipment fault diagnosis technology, the application of temperature changes are mainly reflected in the detection and analysis in the process of fault happened, such as bearing oil shortage and hot test, touch point contact undesirable temperature detection of the electrical equipment, metallurgical furnaces lining corrosion in furnace body temperature monitoring, train axle temperature monitor, spindle box thermal deformation detection, Motor core heating and turn between the short circuit fault detection, transmission line and insulator temperature detection, etc.