Most of these small mechanical gauges are the Bourdon type. If you go too far past the upper range there's a couple small gears inside that can get out of calibration when one of them moves past the end of it's teeth. Depending on what the needle does when it moves past the end determines how much it's off when normal pressure is restored. It's possible to reposition the gearset and check it against a known good gauge but don't use any sharp tools on the tube or bend it too far.
