One limitation to the comparability of pH measurements is the accuracy of the pH values off the standard buffer solutions. Whithin the framework of EUROMET, the first intercomparison of primary measurement devices for pH was carried out in 1994 (EUROMET Project 300). In order to continue the intercomparison, the pH measurements will be performed on phosfate buffer, phthalate buffer and borate buffer solutions. A batch of buffer material will be produced by Merck and divided among the participating laboratories. The pH values will be determined using hydrogen electrode system (E. Merck will use a difference potentiometric cell).
Final Report 1996-12-31
The comparison has been completed and results are available under https://doi.org/10.1088/0026-1394/34/4/12