Main factors affecting the emissivity of infrared thermometers are as follows:
Material type, surface roughness, physical and chemical structure, and material thickness, etc.
When using an infrared radiation thermometer to measure the temperature of a target, the first step is to measure the infrared radiation of the target within its wavelength range, and then the thermometer calculates the temperature of the measured target. Monochromatic thermometers are proportional to the radiation within the frequency band, while dual color thermometers are proportional to the ratio of radiation between two frequency bands.
The infrared thermometer must correctly select the corresponding infrared system:
The infrared thermometer consists of an optical system, a photodetector, a signal amplifier, signal processing, display output, and other components. The optical system concentrates the infrared radiation energy of the target within its field of view, and the size of the field of view is determined by the optical components and their positions of the thermometer. Infrared energy is focused on the photodetector and converted into corresponding electrical signals. The signal is amplified and processed by a signal processing circuit, and then converted into the temperature value of the measured target after being calibrated according to the algorithm and target emissivity of the instrument's internal therapy.
There are three aspects to choosing an infrared thermometer:
In terms of performance indicators, such as temperature range, spot size, operating wavelength, measurement accuracy, response time, etc; In terms of environment and working conditions, such as ambient temperature, windows, display and output, protective accessories, etc; Other factors such as ease of use, maintenance and calibration performance, and price also have a certain impact on the choice of thermometer. With the continuous development of technology, the optimal design and new progress of infrared thermometers provide users with various functions and multi-purpose instruments, expanding their choices.
Determine the temperature measurement range:
The temperature measurement range is an important performance indicator of a thermometer. The coverage range of JTCIN series products is -20 ℃ -+2400 ℃, but this cannot be achieved by one type of infrared thermometer. Each model of thermometer has its own specific temperature measurement range. Therefore, the user's measured temperature range must be considered accurately and comprehensively, neither too narrow nor too wide. According to the blackbody radiation law, the change in radiation energy caused by temperature in the short band of the spectrum will exceed the change in radiation energy caused by emissivity error. Therefore, short waves should be used as much as possible for temperature measurement.
Determine target size:
Infrared thermometers can be divided into monochrome thermometers and two-color thermometers (radiation colorimetric thermometers) based on their principles. For monochrome thermometers, the area of the measured target should fill the thermometer's field of view during temperature measurement. It is recommended that the size of the target being tested exceed 50% of the field of view size. If the target size is smaller than the field of view, the background radiation energy will enter the visual and acoustic symbols of the thermometer and interfere with the temperature reading, causing errors. On the contrary, if the target is larger than the field of view of the thermometer, the thermometer will not be affected by the background outside the measurement area.
