MapDaddy Barometric Correction
 

I have questions regarding it:
Just how exactly does the MapDaddy 4 bar sensor do the barometric correction? There is a barometric correction chart available in Tuner Studio but it's blank, and the DIY Autotune website has always implied that it does it automatically. Is this really the case or do I have to somehow figure out a correction chart?
Thanks to anyone who can help!