<title>Real-time measurement of temperature field by colorimetric method</title>

Abstract

Real-time measurement of temperature field is an important but very difficult problem in metallurgy, welding and various hot working process. The authors proposed a colorimetric method for measuring temperature field with ICCD as sensor. Two filters with different wavelength are mounted on a high speed rotating disk in front of the ICCD. so that two images can be taken by ICCD quickly and successively for the colorimetric estimation. Temperature range which can be detected by the designed device is 1 100-1600 K. The measuring time for one field is less than l2Oms. Due to the inherent law of the method, the distance between the object and device has no effect on the measured results, therefore it does not need calibration for measurement at different position, which is one of the great advantage of the proposed method. keyword temperature field measurement, colorimetry, ICCD, welding 1 . INTRODUCTION Measurement of dynamic temperature field is important in metallurgy, welding and various hot working process. For improving their quality and raising the efficiency, to develop a sensor, which can detect temperature field in real-time, is an important project. Infrared thermal image system is applied extensively in the measurement of temperature field. The system may be divided as opticalmechanical type and non optical-mechanical type. The first one has complex structure, slow response speed, expansive , so it can not measure the temperature in real-time and isn't accepted extensively. The second one includes PtSi staring infrared focal plane arrays. It dispenses with the optical-mechanical scan and has very simple structure. The speed of its response is improved greatly But all infrared thermal image systems applied in measurement of temperature field depend on many factors , such as the emissivity of body, the distance of body, background, calibration etc. There is also a question of cooling for infrared detector 6.7 The temperature field can be measured by colorimetric method with ICCD as sensor. This method has the advantage of conventional two-color measurement method8 . But the range of temperature measurement is small because of small response range of the ICCD by this sensor. This paper introduces the principle of measurement of temperature field by colorimetric method with ICCD two-color thermal images, proposes the method to expand the range of measurement of temperature field by using different shut off time, and structure of ICCD sensor with high speed rotating two-color modulation disk. Finally, the experiments were conducted to veriIy the principle of the proposed method. 0819422959/96/$6.OO SPIE Vol. 2894 / 11 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/15/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx