为了扩展动态测量范围, 提高对较低的激光功率的测量不确定度, 对太阳辐照度绝对辐射计的测量方法进行了研究与改进。首先, 重复测量各个激光功率的响应度, 分析由响应度引入的系统误差对测量不确定度的影响; 其次, 提出改进的测量方法, 通过两次电定标实时修正光功率附近小功率区间的响应度; 最后, 使用新方法和传统方法测量各个功率的激光, 比较测量不确定度。实验结果表明: 根据宽功率区间获得的响应度的相对不确定度为2.7%, 测量较低的激光功率时, 不可忽略由响应度引入的误差。当激光功率低于20 mW时, 改进方法的相对测量不确定度仍为0.1%, 具有更好的稳定性, 补偿了响应度误差。因此, 电定标与光定标差距非常大, 不具备可比性, 需两者结合实现全动态范围定标; 该方法可以扩展动态测量范围, 对于定标太阳辐照度绝对辐射计具有重要意义。

The measure method of Solar Irradiance Absolute Radiometers(SIARs) is investigated and revised in order to extend the dynamic measurement range and improve the measure uncertainty of lower laser power. The sensitivity of each laser power was repeatedly measured. The impact of the system error of sensitivity on the measure uncertainty was analyzed. The revised method was proposed. The sensitivity in the narrow power interval and near the optical power was corrected pass through two electrical calibrations. Different laser powers were measured with the new method and the traditional method. The measure uncertainties were compared. Experimental result indicate that the relative uncertainty of the sensitivity achieved from the wide power interval is 2.7%. The system error of sensitivity cannot be neglect when measuring lower laser power. When laser power is lower than 20 mW, the relative measure uncertainty of the new method is still 0.1%. The new method possess a better stability. The error of sensitivity is compensate. Therefore, the difference between electrical and optical calibration is extremely large, and does not have comparability. The total dynamic range calibration needs the combination of electrical and optical calibration. The dynamic measurement range is extend by the new measure method, which is significant for calibrating SIRAs.