颜色温度和相关色温是光源的重要参量。从色品坐标(u,v)到颜色温度和相关色温的计算过程比较复杂,很难依据国际标准化组织推荐的不确定度评定方法进行分析。介绍了从光谱辐射功率和色品坐标(u,v)的不确定度出发,按照国际标准化组织的推荐方法,得到更为科学合理的颜色温度和相关色温的不确定度评定方法。针对新的国家颜色温度副基准,分别采用基于数学模型的精确方法、近似方法和几何方法对其不确定度进行了评价,并与传统方法进行了比较。采用传统方法得到的计算结果偏高,这是因为传统的计算方法很大程度上基于实验和经验估计,没有将颜色温度的不确定度与光谱辐射功率和色品坐标(u,v)的不确定度之间建立明确的数学关联,在分析过程中存在对某一不确定度源进行重复计算的可能。所述的数学推导方法相对传统方法更为科学合理。

The colour temperature and the correlated colour temperature are important parameters of the sources. Because of the complex calculation process between the colour temperature, the correlated colour temperature and the chromatic coordinate (u,v), it is difficult to analyze the expression of uncertainty according to the international organization for standardization (ISO) guide. Based on the ISO guide to the expression of uncertainty, correlated colour temperature uncertainty is derived from the analytical equation between the chromatic coordinate (u,v) and the colour temperature. Accurate analytical method, approximate calculation, geometrical projection method and traditional method are discussed and compared, which are used to evaluate the uncertainty of the new national secondary standard of colour temperature at National Institute of Metrology (NIM). Traditional uncertainty analysis is mostly based on experimental statistic and experience estimation, and no mathematical relation is found between the colour temperature uncertainty and the spectral irradiance values. The analytical methods described in this paper are more accurate and reasonable.