AN OPTIMAL CALIBRATION DESIGN FOR pH METERS

Routine pH measurements are carried out with pH meter–glass electrode assemblies. The use of these electrodes is subject to various effects, described in this article, producing uncertainties of unknown magnitude. Therefore, the measurement of pH requires a suitable calibration by certified standard buffer solutions traceable to primary pH standards. This article addresses the optimal experimental procedure for the calibration problem to common pH meters, under D- and c-optimality criteria. The relevant calibration data analysis and the results are also presented in detail.