The average
current density,

,
is defined by
where

is the electrode area,

is the local current density and

is an infinitesimal surface element.
Source:
PAC, 1981, 53, 1827
(Nomenclature for transport phenomena in electrolytic systems)
on page 1836
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.