The magnetic field detection means which detect the change of the magnetic field which it occurs

摘要

PROBLEM TO BE SOLVED: To provide an apparatus and a method for detecting metals and a computer readable recording medium which speedily keep up with a characteristic change of signals of an object to be inspected to maintain stable detection sensitivity. ;SOLUTION: When a phase characteristic of a signal of an object to be inspected which is generated by the object subsequent to an environmental change such as a surrounding temperature change or the like changes from a phase characteristic P, a detection phase is shifted sequentially from the phase A by Δθ in a direction in which the signal of the object after the shift becomes smaller than the signal of the object before the shift, whereby the detection phase is made always to keep up with the change of the phase characteristic of the object to be inspected.;COPYRIGHT: (C)1999,JPO