针对纯镁及镁合金的燃点难判定及热电偶测量破坏被测温度场分布、使用寿命短、难以小型化等问题，设计了一种新的比色测温装置。介绍了装置的基本结构及测温原理；提出了根据装置接收的两路光辐射变化的拐点来确定其起燃时间的方法，其对应温度即为燃点温度；利用光纤光谱仪测量纯镁燃烧前后的光谱作为系统波长和带宽选取的参考，计算发射率比值并将其用于温度修正；利用中温黑体炉对比色测温装置进行静态标定，获得静态灵敏度系数；最后以CO2激光器作为热源来点燃纯镁和镁合金AZ91D，同时用比色测温装置和红外测温仪进行燃点测试。实验结果表明，纯镁和镁合金AZ91D测量结果的相对误差分别为1.43%和1.08%。

Due to the difficulties of judgments in magnesium and its alloys′ ignition points and problems of measured temperature field distribution influenced by thermocouples, short lifespan and inconvenient miniaturization, a new kind of colorimetric temperature test device is designed. The basic structure and test principle of this device are introduced. According to the inflection point of changes in two channels of received optical radiation, the burning time is confirmed and the corresponding temperature is just the ignition point. A fiber optic spectrometer is used to test the spectra before and after combustion, which provide a reference for choosing system′s wavelength and bandwidth, and temperature correction is performed with calculating the ratio of emissivity. A temperature of blackbody furnace is used to do static calibration for the colorimetric test device to decide the systematic wavelength and bandwidth. Finally, a CO2 laser is employed as the heat source to ignite pure magnesium and magnesium alloy AZ91D. The colorimetric temperature test device and infrared thermometer are used to do ignition test. The results test show that the relative error of pure magnesium and magnesium alloy AZ91D are 1.43% and 1.08%, respectively.