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Chemistry

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Analytical Chemistry

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Chemical Applications of Statistical Analyses

Random Error in Measurements

Description

Random error in measurements comes from uncontrollable variables that affect data from one trial to the next. These variables can include changes in the environment, imperfections in an instrument, or the natural variation of the thing being measured. Because the direction and size of the error can change from one measuremen...

Transcript

不确定或随机误差由连续测量中的几个不可控变量引起。

由于这些误差既无法预测也无法估计,因此永远不会消除。有时甚至很难识别各个误差源。考虑一个仪器中电噪声的随机误差示例。波动可以有正向和负向,幅度也不同。

由于这些随机变化,不确定的误差是分散的。但是,对于大型数据集,概率的数学定律有助于在平均值或中位数中找到最可能的结果。

在绘制具有随机误差的数据时,值会围绕出现频率最高的中心值在两个方向上分布。随着值从中心值开始升高和降低,出现频率会逐渐下降。这样的分布图称为高斯曲线。

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