白兰地中酒精度测量的不确定度评定

Evaluation of uncertainty of measurement of alcohol content in brandy

目的分析白兰地酒精度测试过程中由系统效应和随机效应产生的不确定度来源。方法根据GB5009.225-2016《食品安全国家标准酒中乙醇浓度的测定》中密度瓶法测定白兰地的酒精度,并按照JJF1059.1-2012《测量不确定度评定与表示》评定,测得白兰地酒精度的不确定度。结果在95%的置信区间下,当酒精度为40.61%vol时,扩展不确定度为0.33%vol(k=2)。结论本方法的不确定度主要来源为样品重复测定时引入的随机效应。

Objective To analyze the sources of uncertainty caused by system effect and random effect in brandy accuracy test.Methods According to GB 5009.225-2016 Determination of ethanol concentration in national standard for food safety, the alcohol content of brandy was determined by density bottle method, and according to JJF 1059.1-2012 Evaluation and expression of measurement uncertainty, the uncertainty of brandy alcohol content was measured.Results Under the 95% confidence interval, when the alcohol content was 40.61%vol, the expanded uncertainty was 0.33%vol(k=2).Conclusion The uncertainty of this method mainly comes from the introduction of random effect in sample repeated determination.