Researching For Industrial Temperature Measurement System Based On The Uncooled IRFPA

In the electricity, petrochemical, metallurgical and other industries and their industrial products, it is significant to strengthen the temperature control and the early warning of the large motors, furnace tube, heating of steel and so on, which can ensure safety in production, improve product quality and production efficiency, reduce energy consumption. In the traditional contact temperature measurement, it is difficult to complete large area, multi-angle, high-precision temperature measurement for the workpiece, Therefore, the Planck blackbody radiation law as the basic principle of non-contact colorimetric temperature measurement came into being. The colorimetric temperature measurement system using the optoelectronic information technology, the digital image acquisition and processing technology, the computer technology and other emerging technologies, achieving the real-time, accurate and high-precision temperature measurement for the workpiece.The colorimetric temperature measurement is based on the Planck blackbody radiation law, it uses the gray scale of double wavelength image to determine the temperature of the workpiece. In the aspect of infrared detector, the operating wavelength of the traditional infrared CCD is0.4～1.1μm, affected by the cut-off wavelength, the error of infrared CCD is very large in industrial low temperature measurement. The operating wavelength of uncooled focal plane array infrared camera is generally between8～14μm, which temperature measurement accuracy can reach0.01℃under the optimum working environment, as a infrared detector, its high precision and wide wavelength range can achieve accurate measurement of low temperatures in the industrial. The UL01011uncooled micro-bolometer is most commonly used as the core photodetector in the uncooled focal plane array infrared camera, in this paper, we used UL01011uncooled micro-bolometer as the experimental photoelectric detector.This paper discussed the basic theory of thermal radiation, the Planck blackbody radiation law and the basic principles of colorimetric temperature measurement; demonstrated the best choice colorimetric double wavelength combination under8～14μm band and the different affection of using different decay rate of attenuator for the temperature measurement range of the uncooled IRFPA camera; introduced the technical parameters of the UL01011uncooled micro-bolometer and its temperature compensation network based on proportion integration differentiation; illustrated the hardware structure of the colorimetric temperature measurement, the flow of software design and the output form of temperature measurement result; finally, the paper discussed the K parameter correction method of hardware error and the approach of image error.