THIS GAGE IS USED TO SET UP AND CALIBRATE THE SENSITIVITY OF THE EDDY CURRENT INSTRUMENT PRIOR TO AND AFTER PERFORMING THE EDDY CURRENT TEST ON THE BALANCE WEIGHT FLANGE SCALLOP OF THE 1ST. COMPRESSOR DISK.THISS GAGE IS DESIGNED TO FIT ON THE DISK ADAPTER OF THE EDDY CURRENT TEST STAND P/N PWA54233.