Patent ID: 11965856
Assignee: NIPPON STEEL CORPORATION
Field: Measurement (Instruments)
Classification: CPC G  B | IPC B  G

Claim 15:
16. The device for detecting a metal residue present in an electric-resistance-welded steel pipe according to claim 15,
wherein a plurality of the detecting coils is disposed in the longitudinal direction of the electric-resistance-welded steel pipe, and
the detector includes
a first signal computation unit configured to average the output signals of the plurality of detecting coils output at the same time to compute a first signal,
a second signal computation unit configured to subtract the first signal from the output signals of the plurality of detecting coils output at the same time to compute second signals respectively corresponding to the plurality of detecting coils,
a third signal computation unit configured to shift horizontal axes of the plurality of second signals by a separation distance between the plurality of detecting coils and adding the plurality of shifted second signals to each other to compute a third signal, and
a first detection unit configured to detect the metal residue present in the electric-resistance-welded steel pipe on the basis of the third signal.