在评定不确定时候应注意修约这一分量导致的不确定度，其有时甚至是主要分量。在本文的测量中，当按照GB/T 5009.37-2003食用植物油卫生标准的分析方法确定的修约间隔（0.01 g/100g）来修约时候，修约引起的不确定度为主要分量；如果按照JJF 1059-1999 测量不确定度评定与表示确定的规则不确定度保留一位有效数字，并以此来修约测量结果时候，此时修约间隔为0.001 g/100g，修约引起的不确定度可以忽略。

When the rounding interval was 0.01 g/100g, the uncertainty from rounding contributed the most to the measurement uncertainty of peroxide value. If the rounding interval for the result was based on the significant figures of the measurement uncertainty, i.e. 0.001 g/100g in the case in this paper, the uncertainty from rounding can be ignored. Attention should be paid to the uncertainty from rounding; sometimes it is the predominant component to the measurement uncertainty of result.