EDDY CURRENT TYPE METAL SENSOR AND EDDY CURRENT DETECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide an eddy current type metal sensor capable of accurately detecting an eddy current of a detected object composed of metal even with a compact and simple configuration, and highly precisely performing detection of presence/absence of metal and measurement of a distance to the metal, and an eddy current detection method capable of accurately detecting the eddy currents of the detected object composed of the metal.;SOLUTION: An eddy current type metal sensor comprises: a first coil 1; a second coil 2; a first oscillation circuit 6 which oscillates including the first coil 1; a second oscillation circuit 7 which oscillates including the second coil 2; a fifth terminal of a microcomputer U1 which receives a reference time signal indicating time from an external device; a measurement part 41 which measures an oscillation frequency in each of the first oscillation circuit 6 and the second oscillation circuit 7 on the basis of the reference time signal; a calculation part 42 which calculates a difference in the oscillation frequency measured by the measurement part 41; and a conversion part 43 which converts the difference calculated by the calculation part 42 as a variation of an eddy current.;SELECTED DRAWING: Figure 4;COPYRIGHT: (C)2018,JPO&INPIT