Zhang Yuzhong, Lu Fucheng, Wang Wenjing, Shu Shuangbao, Dong Jingtao, Tao Xiaojie
School of Instrument Science and Opto-Electronics Engineering, Hefei University of Technology, Hefei 230009, Anhui, China.
Rev Sci Instrum. 2021 May 1;92(5):054902. doi: 10.1063/5.0046410.
The pyrometer based on the charge coupled device (CCD) is a cost-effective and widely used system for temperature measurement in various industrial fields. However, due to the inter-element sensitivity deviations of the CCD-array detector and the influence of various types of noise, the digital signal output of the CCD sensor itself is not completely equal to the ideal value as expected. In this work, based on a classical calibration method, the inter-element sensitivity deviations, dark current, shot noise, and readout-quantization noise for a CCD-based pyrometer are characterized, and the influence of these noises on the temperature measurement accuracy is evaluated quantitatively. Furthermore, the non-uniformity correction coefficient for each pixel is obtained by a simple segment correction method to reduce the inter-element sensitivity deviations, and meanwhile, the Kalman filter is introduced to remove the temperature fluctuations caused by these noises. Experimental results show that mean value of the spatial standard deviation of temperature measurement results in the total measurement range (800-1200 °C) is only 2.2 °C after non-uniformity correction, and the temperature fluctuations can be reduced from 26.6 to 1.98 °C based on the Kalman filter.
基于电荷耦合器件（CCD）的高温计是一种经济高效且广泛应用于各种工业领域温度测量的系统。然而，由于CCD阵列探测器的元件间灵敏度偏差以及各类噪声的影响，CCD传感器本身的数字信号输出并不完全等同于预期的理想值。在这项工作中，基于一种经典校准方法，对基于CCD的高温计的元件间灵敏度偏差、暗电流、散粒噪声和读出量化噪声进行了表征，并定量评估了这些噪声对温度测量精度的影响。此外，通过一种简单的分段校正方法获得每个像素的非均匀性校正系数，以减小元件间灵敏度偏差，同时引入卡尔曼滤波器来消除由这些噪声引起的温度波动。实验结果表明，经过非均匀性校正后，在整个测量范围（800 - 1200°C）内温度测量结果的空间标准偏差平均值仅为2.2°C，并且基于卡尔曼滤波器，温度波动可从26.6°C降低至1.98°C。
