Uncertainty Evaluation in Determination of pH Value in Soil by Potentiometric
Soil pH value is an important indicator in soil analysis,and many soil analysis projects require the selection of corresponding analysis methods based on the soil pH value.The detection results are also related to the soil pH value,which is an important basis for reviewing the results of other projects.This article comprehensively analyzes the uncertainty of soil pH measurement based on the theory of measurement uncertainty evaluation and the potential method.The sources of uncertainty were summarized from five aspects:repeatability of measurement,sample weighing,pre soaking treatment,instrument indication error,and instrument calibration.Each uncertainty component is evaluated in detail,and the relative standard uncertainty and expanded uncertainty of soil pH measurement are synthesized from each uncertainty component.The measurement uncertainty of soil pH was determined to be 8.24±0.03.In the analysis process,the contribution of various uncertainty components to the uncertainty of soil pH measurement is compared,among which the uncertainty component introduced by the calibration of pH standard buffer solution is the largest.
万方数据
维普
