DIN EN 60051-4:1991 Direct acting indicating analogue electrical measuring instruments and their accessories; part 4: special requirements for frequency meters (IEC 60051-4:1984, edition 4); german version EN 60051-4:1989
The standard applies to direct acting indicating analogue frequency meters.
DIN EN 60051-4:1991 history
1970DIN EN 60051-4 E:2017-02 Direct acting indicating analogue electrical measuring instruments and their accessories; part 4: special requirements for frequency meters
2017DIN EN 60051-4 E:2017 Draft Document - Direct acting indicating analogue electrical measuring instruments and their accessories - Part 4: Special requirements for frequency meters (IEC 85/557/CDV:2016); German version prEN 60051-4:2016
1991DIN EN 60051-2:1991 Direct acting indicating analogue electrical measuring instruments and their accessories; part 2: special requirements for ammeters and voltmeters (IEC 60051-2:1984, edition 4); german version EN 60051-2:1989