Post cal on Barometers

A post cal on the barometers used in VERTEX showed a systematic basis. The Ruska reference was tested against the
dead weight piston gauge to verify the error was not in the reference. The results of this test showed an agreement
better than .03 mb between the dead weight and Ruska. Based on this result I believe there was an error in the pre-calibration
of the barometers that created the basis. Below are the post cal results. A simple correction is to subtract the mean error from
the measured value. This results in errors better than 0.2 mb. The other option is to apply the linear correction
resulting in errors better than 0.01 mb.
the data.