袁秉鉴，任屏

(国营5409厂，山西绛县 043606)

两标准光度法测定钢铁中的锰、硅、磷

袁秉鉴，任屏

(国营5409厂，山西绛县 043606)

光度法是以系列标准样品绘制工作曲线然后确定样品测量结果，而往往一系列标准样品的配制和应用成为光度法推广应用的障碍。以钢铁中锰、硅、磷光度法测定为例，介绍遵循“精密度法则”，即“保持影响测量各因素对同一测量系列各个样品影响的一致性”，可选用含量近于测定范围上、下限的两个标准样品确定工作曲线，以此确定样品的测定结果，即两标准光度法。锰、硅、磷10次测定结果的相对标准偏差分别为2.26%，3.63%，6.45%，测量结果的不确定度分别为0.008%，0.006%，0.001%(k=2)。两标准方法测定结果可靠，提高了光度法的测定效率。

光度法；钢铁；锰；硅；磷

AbstractThe spectrophotometric method is based on drawing the working curve of standard sample series to determine the sample measurement results, while the preparation and application of a series of standard samples has become major obstacle to the popularization and application of spectrophotometry. Spectrophotometric determination of Mn，Si, P in iron and steel was taken an example to indicate following the “precision rule”，that was “to maintain infection consistency of each factor for the each sample in the same measurement series”，the working curve could be drawn by two standard samples，which content was close to the measurement range of the upper and lower limits，and reliabie determination results of the samples could be obtained. The relative standard deviation of ten measurement results of Mn，Si , P were 2.26%，3.63%，6.45%, and the uncertainty were 0.008%，0.006%， 0.001%(k=2), respectively. The two standard photometric method is reliable, and it can improve measurement ef ficiency.

Keywordsphotometric method; steel; Mn; Si; P

光度法具有应用范围广、测定含量范围宽、干扰易消除、标准样品易制备、可以多组分联测等优点［1］。但当前光度法都是以“标准系列样品”绘制“工作曲线”确定测定结果［2］。“标准系列样品”至少需要选择4个含量不同的标准样品，这成为光度法广泛应用的一大障碍。为克服光度法的这一不足，笔者经过多年实践探索，发现严格遵循“精密度法则”，即“保持影响测量的各因素对同一测量系列各个样品影响的一致性”，即可用含量近于方法测定含量范围上、下限的两个标准样品的坐标点A，C间的连线作为光度法的“工作曲线”。遵循“精密度法则”愈严，测定结果准确度愈高。严格遵循“精密度法则”是本方法的关键，以钢铁中锰、硅、磷的联测为例，介绍“精密度法则”在光度法测定中的实施细则，为光度法的推广应用提供基础技术。……