As with any measuring instrument you need to check it out. Your Starrett originally came with a 1" diameter standard just for that purpose. If you have access to some gauge blocks you can get a warm fuzzy by checking the measurements at zero, .25",.5" , .875" and 1". If they're all on the line it's good to go. Most micrometers that haven't been abused will be fine. Sometimes the anvils get worn or the mics get dropped and damage occurs to a few of the threads or the spindle gets knocked out of alignment. Not all Chinese measuring instruments are bad, just some are. The issue is figuring out which one you have. Checking anvil flatness and parallelism requires the use of an optical flat.