Title: reference electrode
Long Title: IUPAC Gold Book - reference electrode
DOI: 10.1351/goldbook.R05229
Status: current

Definitions
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Definition (1)
An external electrode system which comprises an inner element, usually mercury–mercury(I) chloride (calomel), silver–silver chloride or thallium amalgam–thallium(I) chloride, a chamber containing the appropriate filling solution and a device for forming a liquid junction, e.g. capillary, ceramic plug, fritted disc or ground glass sleeve.

Related Terms
- ceramic: https://goldbook.iupac.org//terms/view/CT07540
- liquid junction: https://goldbook.iupac.org//terms/view/L03584

Source
- Orange Book, 2nd ed., p. 27 (https://media.iupac.org/publications/analytical_compendium/)

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Definition (2)
An electrode that maintains a virtually invariant potential under the conditions prevailing in an electrochemical measurement, and that serves to permit the observation, measurement, or control of the potential of the indicator (or test) or working electrode.

Related Term
- working electrode: https://goldbook.iupac.org//terms/view/W06686

Source
- Orange Book, 2nd ed., p. 60,65 (https://media.iupac.org/publications/analytical_compendium/)

Related Reference
- PAC, 1994, 66, 2527. 'Recommendations for nomenclature of ionselective electrodes (IUPAC Recommendations 1994)' on page 2533 (https://doi.org/10.1351/pac199466122527)

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Other Outputs
- html: https://goldbook.iupac.org/terms/view/R05229/html
- json: https://goldbook.iupac.org/terms/view/R05229/json
- xml: https://goldbook.iupac.org/terms/view/R05229/xml

Citation: Citation: 'reference electrode' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.R05229
License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.
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Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-06-05T00:39:07+00:00