The purpose of this project is to continue the comparison of primary measurement devices for pH made within EUROMET Project 300 and Project 370. Within this third comparison the pH measurement will be performed on the borate buffer (Na2B4O7 - 10 H20, 0.01 mol/kg) and the carbonate buffer (NaHCO3/Na2CO3, 0.025 mol/kg / 0.025 mol/kg).
A batch of buffer materiel will be produced by Merck and distributed among the participants together with the necessary amount of sodium chloride and hydrochloric acid. A description for the preparation of the buffer solution will be separately given to the participants. The distribution and measurement period is three months. The report should include a short description of the measurement method, the measurement results and the uncertainty calculation according to the ISO Guide to the Expression of Uncertainty in Measurement. A draft report will be circulated for comment within one month efter the deadline fixed for the receipt of the individuel results. It is planned to publish the results of the comparison in Metrologia.
Final Report 1998-09-30
The project has been completed and the report is published in Metrologia https://doi.org/10.1088/0026-1394/37/1/14.