Rogowski Coil - Formulae

Formulae

The voltage produced by a Rogowski coil is

,

where is the area of one of the small loops, N is the number of turns, and is the length of the winding (the circumference of the ring). is the rate of change of the current threading the loop. This formula assumes the turns are evenly spaced and that these turns are small relative to the radius of the coil itself. At high frequencies, the Rogowski coil's inductance will decrease its output. The inductance of a toroid is

V·s/(A·m) is the magnetic constant, is the major radius of the toroid, and is its minor radius.