METHOD AND DEVICE FOR MEASURING BURYING DEPTH OF LONG-SIZED MAGNETIC BODY

摘要

PURPOSE:To measure the burying depth of the long-sized body by passing two orthogonal magnetic force sensors over the long-sized magnetic body and obtaining induced electric power curves, and multiplying the half of the distance two points which are 0.354 time as high as the maximum values of the curves by the reciprocal of a representative fraction. CONSTITUTION:The two magnetic sensors 1 are provided on a sensor conveyor 8 made of a nonmagnetic body at reference distance (d) in their advance direction and passed over the long-sized magnetic body 6. Further, two induced voltage curves E1 and E2 which are maximum right above the magnetic body 6 and symmetric laterally are obtained and its representative fraction d0/d is calculated from the distance d0 between their peaks and reference distance (d). Then, the half of the distance between two points on induced voltage curves which are 0.354 time as high as the maximum values is multiplied by the reciprocal d/d0 of the representative fraction to calculate the burying depth of the long-sized magnetic body 6. Consequently, the burying depth is measured regardless of whether a feeding conductor is present or not as far as the magnetic body is provided.