Brown, R J C; Milton, M J T (2004) Demonstration of the micro-porous structure of silver/silver chloride electrodes and the implications for Harned Cell operation. NPL Report. DQL-AS 001

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Abstract

The stability of silver/silver chloride reference electrodes when moved between different electrolyte solutions is limited by the small amount of solution transferred. The time required for the Ag/AgCl electrode potential to stabilise has been shown to increase with electrode size in an empirical fashion. The results presented in this report suggest the presence of a micro-porous structure in the electrodes that limits the rate at which traces of any previous solutions are diluted by any new solution environment. Operational implications for the stability and accuracy of the Harned Cell used as the primary standard for pH measurements and the certification of primary reference buffers are discussed‡.

Item Type:	Report/Guide (NPL Report)
NPL Report No.:	DQL-AS 001
Subjects:	Analytical Science > Trace Analysis and Electrochemistry
Last Modified:	20 Jul 2018 14:37
URI:	https://eprintspublications.npl.co.uk/id/eprint/3011