it mite be off from someone elses gauge but it dont matter long as you use the same gauge every time , just like tire gauges start comparing them with your buddys next time at the track you mite find a few dead on to yours and they mite be some two to three pounds off from yours long as you stick with the same one you are fine. you mite be running 3 on your camber gauge and it mite be 3.5 on your buddys but o well use the same one every time . i have the gauge you speak of and never had any problems with it but i know it reads different than one of my friends straight up camber gauge. on recalibrating it idk i would call the company and ask them but i wouldnt worry bout it. mite could get the kart on a true flat level surface and take a square and get the hub straight up and down then put your gauge on it and see what it says.