I would not trust the accuracy of a digital level that’s made in China and inexpensive. Sorry, but it’s very true that specs mean nothing to many cheap Chinese vendors. If a $500 Mitutoyo is +/- .05 degrees there’s no way a $100 level is accurate to .01.
When you calibrate the Mitutoyo you flip it around in all orientations, so it gets a true 0 reading even if the surface you are measuring (or the level itself) is not perfectly flat!
When you calibrate the Mitutoyo you flip it around in all orientations, so it gets a true 0 reading even if the surface you are measuring (or the level itself) is not perfectly flat!