摘要
General Great importance is being attached in the electric power in-dustry to the inspection of rotor shafts. This is because defects areusually concentrated at the central part of large forgings for makingrotors, some remnants of them may still remain after the centre borehas been drilled. Some rotors even have quite a number of defects atlocations rather remote from the centre bore. Working conditions for steam turbine rotors are very ex-
