自动电位滴定仪的测量不确定度评定

段绍敏

【摘要】测量不确定度是“根据所用到的信息，表征赋予被测量值分散性的非负参数”。由于在实际的测量中人们的认知不足，测量手段、测量方法、测量仪器及测量条件等不完善，使所得到的测量值具有分散性，也就是说每一次测量所得到的结果不是同一个值，即每次测量所得到的值是以一定的概率分散在某个区间范围内的许多值。测量不确定度就是告诉我们这个区间范围是多少，是说明测量值分散性的一个参数。在仪器校准中都存在不确定度，给出仪器校准结果不确定度，使用者根据这个结果来把握该仪器是否符合使用需求。本文介绍了自动电位滴定仪的测量不确定度评定步骤，包括测量方法、数学模型、分析不确定度的来源、评定数学模型中的各输入量的标准不确定、计算合成不确定度、列出不确定度分量汇总表及扩展不确定度等。

【关键词】自动电位滴定仪；测量；不确定度

【DOI编码】10.3969/j.issn.1674-4977.2023.03.018

Evaluation of Measurement Uncertainty of Automatic Potentiometric Titrator

DUAN Shaomin

（Tongren Inspection and Testing Institute，Tongren 554300，China）

Abstract：Measurement uncertainty is a "non negative parameter that characterizes the dispersion of the measured value based on the information used". Due to peoples lack of cognition in actual measurement，imperfect measurement means，methods，instruments，and conditions，the measured values obtained are scattered，which means that the results obtained from each measurement are not the same value，that is，the values obtained from each measurement are many values scattered within a certain range with a certain probability，and the measurement uncertainty is to tell us what the range is，A parameter that describes the dispersion of measured values. There are uncertainties in instrument calibration. The uncertainty of the calibration result of the instrument is given，and the user can determine whether the instrument meets the use requirements based on this result. This article introduces the steps for evaluating the measurement uncertainty of an automatic potentiometric titrator，including measurement methods，mathematical models，sources of analytical uncertainty，evaluating the standard uncertainty of each input in the mathematical model，calculating the combined uncertainty，listing a summary table of uncertainty components，and expanding the uncertainty.

Key words：automatic potentiometric titrator；measurement；uncertainty

1电计示值误差的测量不确定度评定

1.1测量使用方法和环境条件

1.1.1测量使用方法

1.1.2測量对象

自动电位滴定仪，准确度等级0.05级，测量范围（-2000～+ 2000）mV。滴定管体积为10 mL。

1.1.3环境条件

测量时实验室温度为25℃，相对湿度为48%，室内温度波动变化不大于1℃/h，且无机械振动和电磁干扰。