利用Nordtest准则评定原子吸收分光光度法检测水泥中MgO的不确定度

CNAS要求检测实验室应分析测量不确定度对检测结果的贡献,应评定每一项用数值表示的测量结果的测量不确定度。对于不确定度的评定有多种方法,现拟应用日常检测工作中使用质控样品的检测数据,以及参加能力验证的结果,利用Nordtest准则,对应用原子吸收分光光度法检测水泥中MgO的不确定度进行评定。评定结果,置信度水平为95%,包含因子k=2时,Mg O相对扩展不确定度U=4.86%。结论:所得结果能客观反应实验室应用原子吸收分光光度法检测水泥中MgO的检测质量,Nordtest准则利用实验室质控数据进行测量不确定度的评定,也适用于化学实验室的实际情况。

CNAS requires testing laboratories to analyze the contribution of measurement uncertainty to testing results,and to evaluate the measurement uncertainty of each numerical measurement result.There are many methods for the evaluation of uncertainty.now,we will use the test data of quality control samples and the results of participating in the test of ability in the routine test,and use the Nordtest criterion,to assess the uncertainty in the application of atomic absorption Spectrophotometer to the detection of MgO in cement.The results showed shows that with a confidence level of 95%and a coverage factor of k=2,the relative expanded uncertainty of MgO is U=4.86%.Conclusion:the results can be used to determine the quality of MgO in cement by atomic absorption Spectrophotometer,and the uncertainty of measurement is evaluated by Nordtest criteria using laboratory quality control data,also applicable to the actual situation of the chemical laboratory.