| 摘要 |
PURPOSE:To rapidly and accurately perform the flaw analysis of a tubular material, by calculating a phase angle theta and an absolute value A (the square sum of horizontal and vertical detection outputs of a vortex flaw detector) on the basis of both outputs and reading the kind and depth of the flaw of a tubular material from theta at the time when A reaches a peak. CONSTITUTION:After a probe 7 is sent to the other end of a tubular material 5 under pressure by compressed air of an air gun 10, the tubular material 5 is inspected by a flaw detector 8 while the probe 3 is pulled out to a direction shown by the arrow (a) through a rope 9 by an automatic pull-out apparatus 11 to output horizontal detection output H0 and vertical detection output V0. A phase angle theta=tan<-1>V0/H0 on the basis of the outputs H0, V0 by a phase angle detecting means 13 and an absolute value=H0<2>+V0<2> by an absolute value calculating means 14. The timing when A takes a peak is detected under a condition of A>=A0 (wherein A0 is a set value) by a peak detecting means 15 and said timing and theta are stored in a memory means 17 while the kind and depth of the flaw of the tubular material 5 are calculated by a reading means 16. By this method, the flaw of the tubular material is analyzed rapidly and accurately. |
