Coulometry

Electrochemical measurement principle in which the electric charge required to carry out a known electrochemical reaction is measured. By Faraday’s laws of electrolysis, the amount of substance is proportional to the charge. Coulometry used to measure the amount of substance is a primary reference measurement procedure [VIM 2.8] not requiring calibration with a standard for a quantity of the same kind (i.e. amount of substance). The coulometric experiment can be carried out at controlled (constant) potential (see direct coulometry at controlled potential) or controlled (constant) current (see direct coulometry at controlled current).