Determination of the Depth of Closed Blind Cracks in Non-metal Check Samples and Test Panels for Penetrant TestingNikolay Kalinichenko, Aleksey Kalinichenko, Irina Lobanova, Anna Zaitseva and Egor LobodaMATEC Web Conf., 79 (2016) 01024DOI: https://doi.org/10.1051/matecconf/20167901024