Inspection device having coaxial induction and exciting coils forming a unitary coil unit

摘要

An inspection device has an exciting coil for generating an electromagnetic field and an induction coil which are integrally connected to each other a coaxial relation so as to induce mutual inductance in the induction coil by the electromagnetic field. The mutual inductance caused in the induction coil varies with a given object to be inspected which is present in the electromagnetic field. The object can be inspected by analyzing the change in inductance.