NBN EN 60051-1 : 1999

Introduction
1 General
    1.1 Scope
    1.2 Normative references
2 Definitions
    2.1 General items
    2.2 Description of instruments according to their
          method of operation
    2.3 Constructional features of instruments
    2.4 Characteristic features of instruments
    2.5 Characteristic values
    2.6 Influence quantity, reference conditions,
          nominal range of use and preconditioning
    2.7 Errors and variations
    2.8 Accuracy, accuracy class and class index
3 Description, classification and compliance
    3.1 Description
    3.2 Classification
    3.3 Compliance with the requirements of this
          standard
4 Reference conditions and intrinsic errors
    4.1 Reference conditions
    4.2 Limits of intrinsic error, fiducial value
5 Nominal range of use and variations
    5.1 Nominal range of use
    5.2 Limits of variations
    5.3 Conditions for the determination of variations
6 Further electrical and mechanical requirements
    6.1 Voltage tests, insulation tests and other safety
          requirements
    6.2 Damping
    6.3 Self-heating
    6.4 Permissible overloads
    6.5 Limiting values of temperature
    6.6 Deviation from zero
7 Constructional requirements
    7.1 Sealing to prevent access
    7.2 Scales
    7.3 Indication of out-of-range values of the measurand
    7.4 Preferred values
    7.5 Adjusters, mechanical and/or electrical
    7.6 Effects of vibration and shock
8 Information, general markings and symbols
    8.1 Information
    8.2 Markings, symbols and their locations
    8.3 Markings relating to the reference values and
          nominal ranges of use of influence quantities
9 Markings and symbols for terminals
    9.1 Requirements for markings
    9.2 Earthing (grounding) terminals
    9.3 Measuring circuit terminals
    9.4 Special markings for terminals
10 Tests to prove compliance with this standard
Annex A.1 - Tests
Annex B.1 - Permissible errors and variations
Annex ZA Normative references to international publications
            with their corresponding European publications

Covers direct acting indicating electrical measuring instruments with an analogue display, for example: ammeters and voltmeters; wattmeters and varmeters; frequency meters of pointer and vibrating-reed types; phasemeters, power-factor meters and synchroscopes; ohmmeters, impedance meters and conductance meters; multi-function instruments of the above types. Also applies to some accessories used with these instruments, such as: shunts, series resistors and impedance elements.