Search International and National Patent Collections

1. (WO2014191351) INDUCTIVE SENSOR

Pub. No.:    WO/2014/191351    International Application No.:    PCT/EP2014/060825
Publication Date: Fri Dec 05 00:59:59 CET 2014 International Filing Date: Tue May 27 01:59:59 CEST 2014
IPC: G01V 3/10
Applicants: ICONTROLS K.S.
Inventors: SCHMIDT, Ralf Ph.
In order to detect a material and/or shape parameter of a metal object (3), an inductive sensor (1) is proposed that comprises three flat coils (7, 9, 11) which are stacked such that the coil flat faces are parallel or at least approximately parallel to one another and which partly overlap. The two outer flat coils (7, 11) form either transmission coils for inducing eddy currents in the metal object (3) or receiving coils, the response signal of which addresses the magnetic field of the eddy currents. The two outer flat coils have the same magnetic properties and are operated in a differential circuit which compensates for the influence on the central flat coil (9) in the absence of a metal object (3). In order to increase the sensitivity of the sensor (1), the sensor is operated in a specified detection direction which is parallel to the flat face, said two outer flat coils (7, 1) being offset relative to the central flat coil (9) in opposite directions by the same distance (Δx).