In ac @P04716@, differential pulse @P04716@, derivative @P04716@, square-wave @P04716@, and similar techniques, the maximum value of the component of the current that is associated with the presence of a substance B. Normally this component of the current is faradaic, and the maximum arises because the rate of variation (with @A00424@) of the rate of the charge-transfer process passes through a maximum. Similar maxima arise when this component is non-faradaic (and when B is surface-active rather than electroactive). In a case known to be of the latter type, the term @A00412@ is recommended as being more specific.