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Chemistry

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Analytical Chemistry

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Chemical Applications of Statistical Analyses

How Uncertainty Changes in Calculations

Description

Uncertainty changes as measurements move through calculations. In a multi-step experiment, each measurement adds some uncertainty. Because the steps happen one after another, the uncertainty from one step carries into the next step and affects the final result.

The way uncertainty is combined dep...

Transcript

在实验中,通常需要进行多次算术运算。此处,第一个测量值的不确定性会以级联序列的方式传递到后续测量中。

了解每次测量相关的不确定性,可以估算所有算术运算中由随机误差引起的不确定性。

对于加法和减法运算,结果的绝对不确定度是各不确定度以绝对方差表示后求和所得值的平方根。

对于乘法和除法运算,结果的相对不确定度是将各相对方差计算出的不确定度求和后,再取平方根。

对于指数函数运算,结果的相对不确定度等于底数的相对不确定度乘以指数。

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