I was never aware of any barmetric correction associated w/ the SF-110, either, although I know of certain benches (e.g. FlowData) that require it. I've never seen any noticeable variations when running a calibration check against the supplied plate, either.

Unlike Dwayne's, my calibration tests don't seem to care which way the plate is oriented. However, I have seen a small (but consistent) difference in calibration factors between tests run at 10" and 8"; I check for both, since those are the most common test pressures I use, and adjust the results accordingly.

As far as factoring in the intake / exhaust temp differential into the final calculation, I've done that... but really haven't seen much added value in taking that extra step. Since the consistency w/ the inclined manometer readings has always been good when retesting known ports, the only thing that the temp differential adjustments seemed to do was lower the final intake #s a few cfm and raise the final exhaust #s a few cfm. I really didn't see any improvement in test-to-test consistency with them...