Measurement Uncertainty Calculations for pH Value Obtained by an Ion-Selective Electrode

Area of Science:

• Analytical Chemistry
• Metrology

Background:

• Measurement uncertainty assessment is crucial for chemical assays.
• Traditional methods exist, but computational approaches like Monte Carlo (MC) simulations offer alternatives.

Purpose of the Study:

• To compare the practicalities and outcomes of different measurement uncertainty evaluation methods.
• To analyze the advantages and disadvantages of typical assessment, MC simulations (programmed and spreadsheet-based), and commercial software.

Main Methods:

• Evaluated a two-point calibration pH measurement case study.
• Compared typical uncertainty assessment with MC simulations implemented via custom programs, spreadsheets, and commercial software.
• Assessed methods based on mathematical complexity, software requirements, time, and cost.

Main Results:

• Different methods vary in mathematical transformations, software needs, calculation time, and cost.
• No single method is universally superior; all yield comparable uncertainty assessments for the case study.
• Analyst skill set influences method suitability.

Conclusions:

• The choice of uncertainty assessment method depends on analyst expertise and available resources.
• Comparable results can be achieved using various approaches, from manual methods to sophisticated software.
• Flexibility in method selection ensures reliable uncertainty evaluation in chemical analysis.