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Chemistry

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Analytical Chemistry

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Chemical Applications of Statistical Analyses

Reducing Bias in Measurement Errors

Description

Systematic errors are bias in measurement, and their sources can often be identified and reduced. In this topic, the main categories are sampling, instrumental, methodological, and personal errors. Each one comes from a different part of the experiment, so each one needs a different fix.

Sampling...

Transcript

系统误差根据其来源可分为四种类型——取样误差、仪器误差、方法误差和个人误差。

由于采样方法不当,会导致重复样本之间的变异,从而产生采样误差。优化的采样策略可最大限度地减少此类误差。

仪器误差源于有缺陷的仪器或校准不当 ,可通过定期校准消除这些误差。

方法误差源于分析方法的局限性、试剂的非理想行为以及不正确的假设。可通过使用标准参考物质、空白试验或进行平行独立分析来减少此类误差。

此外,人为误差是由于粗心大意以及分析人员能力有限所致。通过系统化、专注的实验操作以及自动化流程,可以将此类误差降至最低。

如果绝对误差的大小与样本量无关,则称为恒定误差。然而,如果它随样本量系统性地变化,则称为比例误差。

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