[Measurement of the three-phase nonequilibrium of weak amplitude]

A simple and almost general method is proposed for the determination of three-phase unbalances. This is well adapted to the cases of weak unbalances, for which the usual methods are not convenient. For these cases, simple approached formulas are suggested even if exact formulas also are given. The measuring equipment is limited to one instrument only (voltmeter or ammeter) the performances of which are common at the present time. An experimental check corroborates the validity of the method.