NTC thermistor chip produced by EXSENSE Electronics Technology Co., Ltd. with high precision, high sensitivity, high reliability and so on. Due to its resistance value decreases with the increase of temperature and increases otherwise, it plays a role of temperature monitoring and temperature controlling in the infrared temperature measurement system.
With the outbreak of COVID-19, the traditional contact temperature measurement method can no longer meet the current temperature measurement needs. Common temperature measurement technology has been nearly mature after a long time development, with the rapid development of modern society, temperature measurement technology under special conditions (such as high temperature, strong corrosion, strong electromagnetic field conditions or longer distance) is needed. Therefore, the demand for non-contact, long-distance temperature measurement technology is increasing, and the starting point of design of infrared thermometer is based on this.
Non-contact infrared temperature measurement is also called radiation temperature measurement. Generally, thermoelectric or photoelectric detector is used as the detection element, and NTC thermistor chip is used as the component of temperature monitoring and temperature controlling. Infrared temperature measurement system is relatively simple, which can achieve a large area of temperature measurement, and can be measured at a point on the measured object temperature measurement. And infrared thermometer can be portable, and can be fixed, easy to use; It has the advantages of simple manufacturing process, low cost, no contact with the measured object when measuring temperature, has the advantages of short response time, no interference with the measured temperature field, long service life, convenient operation, etc.. However, the infrared temperature measurement system in the measurement process, will also be affected by the object emissivity, temperature measurement distance, smoke, water vapor and other external factors, resulting in a large measurement error. Therefore, adding a thermistor chip to the infrared temperature measurement system can effectively reduce the measurement error and facilitate the real-time acquisition of temperature data.
The principle of infrared temperature measurement system is the Planck's Blackbody radiation law. In nature, all objects higher than absolute zero are constantly radiating energy outward. The size of outward radiation energy and its distribution by wavelength are closely related to its surface temperature. The hotter an object is, the more infrared radiation it emits. Blackbody radiation has several characteristics:
First, at any temperature, the spectral radiance of the blackbody radiation varies continuously with the wavelength, and each curve has only one maximum value;
Second, with the increase of temperature, the wavelength corresponding to the maximum of spectral radiance decreases. This indicates that the proportion of short-wavelength radiation in blackbody radiation increases as the temperature increases;
Third, with the increase of temperature, the blackbody radiation curve increases overall, that is, at any given wavelength, the spectral emissivity corresponding to higher temperature is also larger, and vice versa.