Key Comparisons in Electrochemistry: Significance to Metrology and Global Trade
Kenneth W. Pratt, David L. Duewer
Standard materials certified using electrochemical techniques include many of the most-used certified reference materials (CRMs). These CRMs provide traceability for some of the most-frequently-performed chemical measurements, including pH, electrolytic conductivity, and titrimetry. International recognition of these CRMs is an important link in global trade. International traceability among National Metrology Institutes (NMIs) is evaluated by means of Key Comparisons (KC), performed under the aegis of the International Conference on Weights and Measures (CIPM). The Consultative Committee on Amount of Substance Metrology in Chemistry (CCQM), set up by the CIPM in 1993, is responsible for KCs in chemical metrology. The CCQM has organized seven advisory Working Groups (WG), including the Electrochemical Analysis WG (EAWG). These WGs advise the CCQM in their areas of expertise. The EAWG administers those KCs related to electrochemical analysis. This paper summarizes how KC results are obtained and how KCs function as the benchmark for international traceability. Using specific experiences from NIST participation in electrochemical KCs, the talk also illustrates how the experience gleaned through these KCs has increased understanding of the factors that influence the measurements under evaluation. Such experience is reflected in the assigned uncertainty of the corresponding CRMs. These CRMs are widely used for calibrations. Any improvement in the assigned uncertainty of the CRM is reflected in the uncertainties of corresponding secondary, real world measurements. Thus, any improvement gleaned from a KC is of interest not only to NMIs, but also to industrial and other users of the corresponding CRMs.
and Duewer, D.
Key Comparisons in Electrochemistry: Significance to Metrology and Global Trade, 2009 NCSL International Workshop and Symposium, San Antonio, TX
(Accessed June 4, 2023)