Calibration of the MSE diagnostic is technically straightforward but complicated by a number of practical considerations that potentially introduce systematic errors. These include the fact that in many instances only a portion of the diagnostic can calibration under laboratory conditions and the uncertainties resulting from inexact knowledge of the location of the beam centerline, to name just two. Uncovering systematic errors is difficult as they can be masked by overestimating the statistical errors in the calibrated quantities. Thus alternative means of validating the calibration and correcting it are of interest. Below we present a semi-empirical means of achieving this goal through the use of current ramp shots