Device for measuring induction in the presence of metal walls magnetic

This invention relates to a device for measuring induction of a medium (8) in the presence of a wall (6) of substantially cylindrical shape, and magnetic metal, comprising: - means (24 ) for saturating the magnetic wall, - means (28) for inducing a signal in the medium beyond the magnetic wall, - receiving means (30, 32) a signal retransmitted by the medium in response to the previously induced signal, characterized in that the means for saturating the magnetic wall are constituted by at least two magnetic circuits (2, 4) intended to be applied directly against the metal wall during the measurement by induction.