·Table of Contents ·Methods and Instrumentation | Computerized Eddy Current Flaw Detector VD-89NM with Higher Reliability of Detection and Danger Level estimation of Stress-corrosion cracks when Inspecting Gas Pipeline under Stress-CorrosionV.F.Muzhitsky, V.A.KarabtchevskiMSIA "Spectrum", Russia S.V.Karpov VNIIGAZ, Russia Contact |
Fig 1: Summary magnetic field Hmlt. of two cracks,Hmon.-magnetic field of alone crack for cases,when: a.)-cracks are on a distance more than x_{0};b.)-cracks are on distance x_{0}(-half a width of area of positive magnetic field of alone crack);c.)-cracks are on a distance less than x_{0}. |
Fig 2: Error D of summary magnetic field evaluation of two equal cracks under different z for the cases of different Dx:a.) Dx = 0,9mm;b.) Dx = 2,5mm;c.) Dx = 5,4mm;d.) Dx = 10,3mm. |
Fig 3: Magnetic field maximum H_{0} of alone crack dependence to compare with magnetic field maximum Hs of equal cracks dependence of gap number z. | Fig 4: Gap number z dependence of crack number h,for pare of which magnetic field maximum of alone crack is equal to the same of spot of equal cracks with changing of Dx : Dx1 > Dx2 > Dx3. |
Fig 5: Topography and profyle of crack depth estimations distribution on part of surface of real pipe of main pipeline |
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