摘要
目的通过不确定度评定对水中耗氧量测定结果临界值进行判断。方法根据JJF1059—1999《测量不确定度评定与表示》对《生活饮用水卫生规范》(2001)中耗氧量的酸性高锰酸钾滴定法的测量不确定度进行分析评定。结果水中耗氧量测定的A类相对标准不确定度为0.584%,B类不确定度为0.781%。其中,使用25ml滴定管引入的相对标准不确定度分项为0.708%,水样体积引入的相对标准不确定度分项为0.056%,校正高锰酸钾标准溶液引入的不确定度分项为0.325%;合成相对标准不确定度为0.975%,扩展不确定度为1.95%。结论根据不确定度评定结果犤(3.08±0.06)mg/L犦可以判定受污染的水样中耗氧量超标,25ml滴定管的使用对不确定度贡献最大。
Objective To estimate the marginal value of the chemical oxygen demand （COD） in drinking water by evaluation of uncertainty. Methods Aecording to Evaluation and Expression of Uncertainty in Measurement （JJF1059--1999）, analysis of measure uncertainty of the chemical oxygen demand determined by acidic potassium permanganate titrate prescribed in Sanitary Standards for Drinking Water （2001） was conducted. Results The type A relative standard uncertainty was 0.584%, type B was 0.781%, in which the sub-item uncertainty led by using 25 ml burette was 0.708%, the water sample volume was 0.056%, the adjusted potassium permanganate standard solution was 0.325%; the relative combined standard uncertainty was 0.975%, the expanded uncertainty was 1.95%. Conclusion According to the result of the uncertainty （3.08±0.06） mg/L, COD in the polluted sample exceeds the limit, the use of 25 ml burette produced the most contribution to the uncertainty.
出处
《环境与健康杂志》
CAS
CSCD
北大核心
2006年第3期269-270,共2页
Journal of Environment and Health
关键词
水
耗氧量
不确定度
Water
Chemical oxygen demand
Uncertainty
