DEVICE FOR DETECTION OF CLEANING PISTON IN PIPELINE Russian patent published in 1998 - IPC

FIELD: methods of cleaning of pipeline internal surfaces. SUBSTANCE: device has cleaning piston on which source of permanent magnetic field is installed and receiving for fixing the moment of passage of cleaning piston is installed on external side of pipeline. Included in receiver circuit are differentiator, comparator, trigger, pulse generator, summing amplifier and setter of initial level and flux-gate meter provided with additional winding. Introduced circuit in steady-state regime makes it possible to minimize the value of projection of resulting vector of magnetic field intensity on longitudinal axis of flux-gate meter. EFFECT: higher efficiency. 1 dwg