There were concerns about possible damage to the air gap
face of the laminated core so an inspection robot with
camera and Chattock coil were inserted in the space
between salient poles to survey the complete 3.95 m length
of the core. By use of the EL CID test at 4% excitation no
electromagnetic imperfections were detected in excess of
50 mA quadrature current adjacent to any of the 132 slots
[29]. The maximum for acceptance is 100 mA [17].