BRITISH STANDARD
Direct acting indicating
analogue electrical
measuring instruments
and their accessories —
Part 6: Specification for special
requirements for ohmmeters
(impedance meters) and conductance
meters
click below BS 89-6:1990 EN 60051-6: 1989 IEC 51-6:1984 pdf free download
click here BS 89-5:1990 EN 60051-5: 1989 IEC 51-5:1985 pdf free download