The SI unit of electric potential, potential difference, and electromotive force. It is defined as the potential difference between two points on a conductor when the current flowing is one ampere and the power dissipated between the points is one watt. In practice volts are measured by comparison with a Weston standard cell using a potentiometer.
This unit replaced the international volt (Vint) as the standard unit of voltage: one Vint equals 1.000 34 V.