Explanation of Signal Processing Function of Infrared Thermometer
Signal processing function: Different from continuous processes, measuring discrete processes (such as part production) requires infrared thermometers to have signal processing functions (such as peak holding, valley holding, average value). When measuring the temperature of the glass on the conveyor belt, it is necessary to maintain the peak value and transmit the output signal of its temperature to the controller.
Infrared temperature measurement technology is playing an important role in product quality control and monitoring, equipment online fault diagnosis, safety protection, and energy conservation. In the past two decades, non-contact infrared thermometers have rapidly developed in technology, continuously improved in performance, expanded in applicability, and increased in market share year by year. Compared to contact temperature measurement methods, infrared temperature measurement has advantages such as fast response time, non-contact, easy to use, and long service life.
The selection of an infrared thermometer can be divided into three aspects: performance indicators, such as temperature range, spot size, working wavelength, measurement accuracy, response time, etc; In terms of environment and working conditions, such as environmental temperature, window, display and output, protective accessories, etc; Other options, such as ease of use, maintenance and calibration performance, and price, also have a certain impact on the selection of temperature detectors. With the continuous development of technology, the excellent design and new advancements of infrared thermometers provide users with various functions and multi-purpose instruments, expanding their choices.
Explanation of the signal processing function of the infrared thermometer to determine the temperature measurement range: The temperature measurement range is the most important performance indicator of the thermometer. Each model of thermometer has its own specific temperature measurement range. Therefore, the user's measured temperature range must be considered accurate and comprehensive, neither too narrow nor too wide. According to the blackbody radiation law, the change in radiation energy caused by temperature in the short wavelength of the spectrum will exceed the change in radiation energy caused by emissivity error. Therefore, it is recommended to choose short wavelength as much as possible for temperature measurement.
Determine target size: Infrared thermometers can be divided into monochrome thermometers and dual color thermometers (radiation colorimetric thermometers) based on their principles. For a monochromatic thermometer, when measuring temperature, the area of the measured target should fill the field of view of the thermometer. It is recommended that the size of the tested object exceed 50% of the field of view. If the target size is smaller than the field of view, the background radiation energy will enter the visual sound symbol of the thermometer to interfere with the temperature measurement 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.
The explanation of the signal processing function of infrared thermometer determines the optical resolution (distance sensitivity). The optical resolution is determined by the ratio of D to S, which is the ratio of the distance D between the thermometer and the target to the diameter S of the measuring spot. If the thermometer must be installed away from the target due to environmental conditions, and to measure small targets, a high optical resolution thermometer should be selected. The higher the optical resolution, i.e. increasing the D: S ratio, the higher the cost of the thermometer.
