环缝偏心内照法N,(L)3和Leff参数计算式的探讨
배봉편심내조법N,(L)3화Leff삼수계산식적탐토
DISCUSSION ON THE CALCULATION OF THE PARAMETERS N,(L)3 AND Leff FOR RADIOGRAPHIC INSPECTION OF CIRCUMFERENTIAL WELDS WITH SOURCE INSIDE BY OFF-CENTRE METHOD