AeroPod, PowerPod and Newton

I see that is a ,,calibrated ride” if Im accessing the ,,Check calibration Usong Out & Back Ride”. What is this?
On the ,,original” its shows(beside others differents) 171,9 avg w and 217NP while the ,,calibrated one” shows 214,5 avg and a 273W NP

Oh, I think this is without any draft, but I still dont understand what this ,,checking calibration” is. Is there a Isaac tutorial?

Please post .ibr ride files