自動電位滴定儀的測量不確定度評定

段紹敏

【摘要】測量不確定度是“根據所用到的信息，表征賦予被測量值分散性的非負參數”。由于在實際的測量中人們的認知不足，測量手段、測量方法、測量儀器及測量條件等不完善，使所得到的測量值具有分散性，也就是說每一次測量所得到的結果不是同一個值，即每次測量所得到的值是以一定的概率分散在某個區間范圍內的許多值。測量不確定度就是告訴我們這個區間范圍是多少，是說明測量值分散性的一個參數。在儀器校準中都存在不確定度，給出儀器校準結果不確定度，使用者根據這個結果來把握該儀器是否符合使用需求。本文介紹了自動電位滴定儀的測量不確定度評定步驟，包括測量方法、數學模型、分析不確定度的來源、評定數學模型中的各輸入量的標準不確定、計算合成不確定度、列出不確定度分量匯總表及擴展不確定度等。

【關鍵詞】自動電位滴定儀；測量；不確定度

【DOI編碼】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電計示值誤差的測量不確定度評定

1.1測量使用方法和環境條件

1.1.1測量使用方法

1.1.2測量對象

自動電位滴定儀，準確度等級0.05級，測量范圍（-2000～+ 2000）mV。滴定管體積為10 mL。

1.1.3環境條件

測量時實驗室溫度為25℃，相對濕度為48%，室內溫度波動變化不大于1℃/h，且無機械振動和電磁干擾。