Metrology Chemistry I: Calibration of a pH meter and Quality Control
DOI:
https://doi.org/10.5377/universitas.v1i1.1627Keywords:
Chemical metrology, pH meter calibration, control charts in pH measurement, quality control in pH measurementAbstract
The main objective of this study is to establish a reliable methodology for calibrating a pH meter using a pH calibrator and certified pH reference solutions. First, the calibration specifications of the pH meter declared by the manufacturer were verified using a pH calibrator. The linearity of the electrode potential response for different pH values was checked, and the efficiency of the electrode was evaluated, yielding a value of 98.39%. The calibration model was determined between the pH response of the instrument and the pH values established in certified reference solutions of pH 4.00, 7.00, and 10.00, resulting in a slope of 1 and an intercept of 0, indicating the good performance of the instrument. Finally, a study of repeatability was conducted over five consecutive days using Bartlett's test to compare the precision of each series of results and one-way ANOVA to compare the means of each day. Control charts for the pH of the certified reference solutions were also created to maintain quality control in routine measurements.
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