CIPM MRA COMPARISON REPORTS
CCQM-K73.2018.4
Amount content of H+ in an HCl solution
Published on 20/02/2026 - © 2026 F. Bastkowski et al
Citation F. Bastkowski et al 2026 CIPM MRA Comparison reports
Authors
F. Bastkowski Physikalisch-Technische Bundesanstalt (PTB) Germany 
P. P. Borges Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO) Brazil
Dániel Nagy Government Office of the Capital City Budapest (BFKH) Hungary
Abstract
The CCQM key comparison K73.2018.4 is a follow-up comparison of CCQM K73.2018. It was performed to demonstrate the capability of the participating institutes to measure the amount content of H+ in hydrochloric acid of 0.1 mol·kg-1 molality. Three NMIs participated in this comparison with PTB being the linking lab. The comparison was coordinated by PTB.
The sample showed a slight but significant instability by loss of water of around 0.13μmol kg-1 d-1 corresponding to 0.006 % over the measurement period. The results were
corrected for this instability.
The results of this subsequent key comparison showed significant deviations from the KCRV.
The sample showed a slight but significant instability by loss of water of around 0.13μmol kg-1 d-1 corresponding to 0.006 % over the measurement period. The results were
corrected for this instability.
The results of this subsequent key comparison showed significant deviations from the KCRV.