Side-by-side reference

Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

First referenceCompare with

Symbols

Indicating instrument general symbol

In IEC-style diagrams an indicating instrument is drawn as a circle, and the asterisk inside is replaced by the unit symbol or quantity, such as V, A, Hz or cos φ. The general form is useful in legends and in early design drawings when the exact instrument is not yet chosen.

Drawing use: SLD / Schematic
Application: Metering & protection
Reference family: IEC

A distinction that matters

The circle is the indicating form; recording instruments use a square and integrating instruments use a rectangle with a band.

Full reference

Symbols

Voltmeter

A voltmeter indicates electrical potential difference between its measurement inputs. The drawing identifies the measured conductors and any instrument transformer or selector associated with those inputs.

Drawing use: SLD / Schematic
Application: Metering & protection
Reference family: IEC / Manufacturer

A distinction that matters

A voltmeter indicates voltage; a voltage relay issues an output according to a voltage condition.

Full reference

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.