基于工业相机的近红外比色法测温研究OA

The image colorimetric temperature measurement technology based on the theory of object spontaneous ra⁃diation and blackbody radiation has been widely applied in engineering,but it suffers from limitations such as a rela⁃tively high lower temperature measurement limit in the visible light band and higher requirements for sensors in the near⁃infrared band.Based on the characters such as high reliability,low cost,compact structure and flexible con⁃trol,this paper conducts research on near⁃infrared colorimetric temperature measurement using a cost⁃effective gener⁃al industrial camera.Through calibration with a standard blackbody furnace,the correspondence between the intensi⁃ty ratio of dual bands(900 nm and 800 nm)and the blackbody temperature is established.The experimental results indicate that both the 900nm/800nm radiation strength ratio and the corresponding measurement sensitivity monotoni⁃cally increase as temperature decreases within 400～1 200℃.The available lower limit for near⁃infrared colorimetric temperature measurement is no higher than 500℃and the relative measurement error is generally lower than±1.5％.Visible light colorimetric temperature measurement using the same camera is applicable above 700℃with slightly higher measurement sensitivity within the range of 700 to 1 200℃.However,to achieve the same image grayscale level,it requires a significantly longer exposure time compared to the near⁃infrared condition.A simplified analysis of the experimental conditions was conducted based on the camera sensor's nominal response characteristics and black⁃body radiation theory.The trend of the calculated results for near⁃infrared temperature measurement agrees well with the experimental data.The technical approach proposed in this paper provides an effective and high cost⁃effectiveness solution for wide⁃temperature⁃range and dynamic process temperature measurement in engineering applications.