BS 7194:1990

Foreword
Committees responsible
Specification
1. Scope
2. Definitions
3. Classification
4. Reference conditions and intrinsic errors
5. Nominal range of use and variations
6. Electrical and mechanical requirements
7. Constructional requirements
8. Information, general markings and symbols
9. Markings and symbols for terminals and connectors
Appendices
A. Recommended tests
B. Permissible errors and variations
Tables
1. Reference conditions and tolerances for testing
    purposes relating to the influence quantities
2. Limits of the nominal range of use and permissible
    variations
3. Symbols for marking instruments and accessories
4. Overloads of short duration
Figures
1. Test apparatus for variation due to common mode
    voltage
2. Test apparatus for variation due to peak factor
    of the measurand
3. Effect of temperature

Requirements for instruments intended for measuring analogue quantities of voltage and/or current. Such instruments will also measure non-electrical quantities provided the relationship between the indicated quantity and the measurand is known.

This standard specifies requirements for the performance of electronic measuring instruments with a digital display intended for measuring analogue quantities of voltage and/or current.

It also applies to instruments for indicating other quantities including non-electrical quantities, provided that the relationship between the indicated quantity and the measurand is known.

This standard applies to self-contained instruments having their own enclosure, terminals, etc., and also to instruments for fitting in an enclosure where the enclosure is not provided by the supplier of the instrument [original equipment manufacture (OEM) instruments].

This standard applies only to instruments measuring current and voltage at d.c. and at a.c. at distribution system frequencies and their harmonics. It applies to the digital parts of an instrument having a combined analogue/digital display.

This standard does not specify requirements concerning dimensions of instruments and does not apply to instruments having a digital or coded measurand input. It does not apply to special purpose instruments which are covered by their own British Standards and contains no requirements for the visibility of the display. It also does not apply to accessories.

NOTE 1 The values of a.c. quantities given in this standard are r.m.s. values unless otherwise stated.

NOTE 2 The publications referred to in this standard are listed on the inside back cover.