N Pin Gauge AB Special gauge AP Inspection Plan (ATOS) P R Gauge AC Thickness Gauge AQ Spring tester Q Limit Gauge AD Multimeter AR Insulation resistance tester R Contour Instrument AE Flux tester AS Bore Gauge S Rockwell hardness tester AF Visual inspection AT Plug gauge T Vickers hardness tester AG Taper gauge AU Gear tester U Micro Vickers hardness tester AH Resistance meter AV Image measuring device V CMM AJ Block Gauge AW Micro protractor W 3D Microscope AK Rubber hardness tester AX Screw gauge X Surface roughness tester AL Universal tester AY Dielectric strength tester Y Limit sample for surface roughness AM Color Map (ATOS) Z Scale AN Wall caliper