IEC 60051-2-2018 pdf download.Direct acting indicating analogue electrical measuring instruments and their accessories – Part 2: Special requirements for ammeters and voltmeters.
This part of IEC 60051 applies to direct acting indicating ammeters and voltmeters having an analogue display.
NOTE For multi-function instruments, see IEC 60051 -7.
It also applies to:
• direct acting indicating ammeters and voltmeters whose scale marks do not correspond directly to their electrical input quantity, provided that the relationship between them is known;
• direct acting indicating ammeters and voltmeters 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.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60051 -1 :201 6, Direct acting indicating analogue electrical measuring instruments and their accessories – Part 1: Definitions and general requirements common to all parts
IEC 60051 -9, Direct acting indicating analogue electrical measuring instruments and their accessories – Part 9: Recommended test methods
IEC 61 869-2, Instrument transformers – Part 2: Additional requirements for current transformers
3 Terms and definitions
See IEC 60051 -1 :201 6.
4 Description, classification and compliance
See IEC 60051 -1 :201 6.
5 Requirements
5.1 Reference conditions
See IEC 60051 -1 :201 6.
5.2 Limits of intrinsic uncertainty, fiducial value
5.2.1 Limits of intrinsic uncertainty
See IEC 60051 -1 :201 6.
5.2.2 Correspondence between intrinsic uncertainty and accuracy class
See IEC 60051 -1 :201 6.
5.2.3 Fiducial value
5.2.3.1 The fiducial value for an ammeter or a voltmeter corresponds to the following.
5.2.3.2 The upper limit of the measuring range for the following:
• instruments with the mechanical and/or electrical zero at one end of the scale;
• instruments with the mechanical zero outside the scale irrespective of the position of the electrical zero;
• instruments with the electrical zero outside the scale irrespective of the position of the mechanical zero.
The class index is marked using Symbol E-1 given in Table 6 of IEC 60051 -1 :201 6 (see Clause 6 of IEC 60051 -1 :201 6).
5.2.3.3 The sum of the electrical values:
The sum of the absolute values of the upper and lower limit of the measuring range when both the mechanical and the electrical zeros are displaced within the scale.
The class index is marked using Symbol E-1 given in Table 6 of IEC 60051 -1 :201 6 (see Clause 6 of IEC 60051 -1 :201 6).
5.2.3.4 The span for an instrument:
The span for an instrument whose scale marks do not correspond directly to its electrical input quantity.
The class index is marked using Symbol E-4 given in Table 6 of IEC 60051 -1 :201 6 (see Clause 6 of IEC 60051 -1 :201 6).IEC 60051-2 pdf download.