ČSN EN IEC 60051-3

This part of IEC 60051 applies to direct acting indicating wattmeters and varmeters having an analogue display. NOTE - For multi-function instruments, see IEC 60051-7. It also applies to: - non-interchangeable accessories (as defined in 3.1.23 of IEC 60051-1:2016) used with wattmeters and varmeters; - a combination of the instruments and the accessories provided that the adjustments have been made for the combination; - direct acting indicating electrical measuring instruments whose scale marks do not correspond directly to their electrical input quantity, provided that the relationship between them is known; - instruments and accessories having electronic devices in their measuring and/or auxiliary circuits. This document does 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.