Part 2 of the standard applies to direct acting indicating ammeters and voltmeters having an analogue display. NOTE For multifunction instruments, see Part 7. It also applies to: " direct acting indicating ammeters and voltmeters whose scale marks do not correspond directly to its electrical input quantity, provided that the relationship between them is known; " direct acting indicating ammeters and voltmeters and accessories having electronic devices in their measuring and/or auxiliary circuits. These standards do not apply to: " special purpose instruments which are covered by their own IEC standards; " special purpose devices which are covered by their own IEC standards when they are used as accessories.