TY JOUR TI Flaw Detector A1550 IntroVisor for Testing of Non-Standard Welding Joint KW ultrasonic testing KW digital focused array KW welded joints KW antenna array JO NDT World AU Meleshko, N.V. AU Gazizova, G.G. AU Abramenko, D.N. AU Mariin, M.A. AU Konnova, E.S. PY 2019 IS 22 PB LLC SVEN