keithley DMM2001 200ma range not well ,how can i calibration the current

[leon1314]

i  have one keithely DMM2001 200ma not well , when i source +-100MA to 2001, the 2001 test value is about +100.8693ma/-100.8765ma ,when i calibrate the 2001 , i can't find the current calibration ,why ?Is the instrument version too low?? the version is B14  /A02  . thank you .