能见度仪校准系统的不确定度评定分析

Uncertainty analysis of the calibration system of visibility meter

能见度仪校准系统作为能见度校准的标准器,其不确定度直接影响到前向散射式能见度仪的校准结果。介绍了国家级能见度仪校准实验室的能见度仪校准系统的组成和校准方法,分析了校准系统不确定度的主要来源,依据国家计量校准规范JJF 1059.1-2012《测量不确定度评定与表示》,利用能见度测量数据,对校准系统A类和B类不确定度进行了评定分析,并对3台前向散射式能见度仪进行了校准试验。结果显示,整个校准系统在能见度3 000 m以下,扩展不确定度为5.8%,校准后的3台前向散射式能见度仪在100、500、1 000、1 500、2 000、3 000 m六个测试点的相对误差,最大为7.8%,最小为1.8%,满足能见度仪校准和实际观测要求。

The visibility meter calibration system is the standard equipment for visibility calibrating, and its uncertainty directly affects the calibration results of forward scattering visibility meter. In this article, the structure, specification and calibration method of the visibility meter calibration system of the national visibility meter calibration laboratory are introduced, the main uncertainty source of the calibration process is analyzed, according to the National Calibration Specification of JJF 1059.1-2012 Evaluation and Expression of Uncertainty in Measurement, Type A and Type B uncertainty of the calibration system are evaluated using the visibility data, meanwhile, three forward scatter visibility meters are calibrated using the calibration system. Results show that the uncertainty of the system below 3000 m visibility is 5.8%, after calibration, the biggest and smallest relative errors of three forward scatter visibility meters at 100,500,1 000,1 500,2 000,3 000 m are 7.8% and 1.8% respectively, which can meet the visibility meter calibration and operational measuring requirements.