1. Comparison of buffer materials 1:3,5 primary phosphate buffer
2. Comparison of buffer Potassium hydrogen phthalate (RVS)
A batch of buffer material is produced and divided between the collaborating laboratories.
The pH value is determined using a comparison hydrogen electrode cell at Merck and hydrogen electrode systems at PTB, University of Milano, OMH, GUM and Radiometer.
The pH value is determined at 15 °C, 25 °C and 37 °C.
Final Report 1994-04-30
The comparison has been finished and results are published in Metrogia https://doi.org/10.1088/0026-1394/33/1/14.