That's pretty brutal, but about right for CHEAP gauges, I wonder if they 'exercise' them first before 'calibrating' them? As a power station Instrument Technician I had to check cal/recal gauges almost daily. Though decent Budenburg gauges had screw clamped adjustable linkages, with 0.5% cal being our normal standard it could take several goes to get them right, still doing comparator calibration checks in the current job, they won't buy me a deadweight tester.