基于图像测量技术的双波长测温仪在线校准方法

摘要

红外测温的方法具有非接触、能够测量极高温度的特点，但其测温精度易受材料自身和环境的影响，针对静电悬浮材料实验装置中双波长测温仪温度测量存在偏差的问题，设计了一种基于图像测量技术的在线校准方法。采用CCD相机获取测温样品的图像，通过边缘提取拟合计算样品体积随温度的变化，与材料自身实际的热膨胀系数对比，修正双波长测温仪的发射率比值。通过对纯金属锆的实验，比对校准后测量的熔点温度，验证了该在线校准方法。%Infrared thermometry method have the advantages of non-contact and extreme high temperature measurement .But its measurement accuracy was affected by the materials and environments .An online calibration method based on image technique was designed to solve the measurement deviation problem of the dual-wavelength thermometer in the electrostatic levitation facility .The sample images were recorded by CCD camera .The image edge was extracted to calculate the volume expansion as a function of tem-perature .By comparing it with the thermal expansion coefficient of the material ,the ratio of the dual-wavelength emissivities was cal-ibrated .A pure Zr sample was experimented to calibrate the thermometer .By checking the melting temperature of the Zr sample ,the calibration method is verified .