In the calibration view log, the max error is reporting the maximum deviation of all the points taken. The value reported by 2 sigma is twice the standard deviation of all the points taken while performing the calibration. 2 Sigma is used to determine whether the arm passes or fails calibration. The value of 2 sigma has to be less than the single point accuracy of the arm for it to pass calibration.
calibration, view log, 2 sigma, max error