PROCESS OF NONDESTRUCTIVE TEST OF SURFACE LAYER OF METAL Russian patent published in 1998 - IPC

FIELD: nondestructive testing. SUBSTANCE: specified current is passed through tested object and standard and voltage emerging on section of surface is measured. Then second current is additionally passed in opposite direction and voltage is measured. Value of second current is selected so that zero resulting voltage is obtained across standard. Thickness and electric conductivity of surface layer are determined by obtained values of voltage and diagram plotted with allowance for location of points of current input and voltage pick-up on surface of tested object and standard. EFFECT: enhanced authenticity of process. 2 dwg