In chronopotentiometry and related techniques, the time that elapses between the instant
at which current is applied and the instant at which the concentration of an
electroactive substance B at the electrode-solution
interface becomes indistinguishable from zero. In experimental practice the latter time is
often taken to be the instant at which the rate of variation of the potential of the
indicator electrode attains a maximum value.
Source:
PAC, 1985, 57, 1491
(Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations
1985))
on page 1504