# Indicating instrument general symbol

Canonical URL: https://eloragrid.ai/symbols/indicating-instrument-general-symbol
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: *
Drawing use: SLD, Schematic
Reference families: IEC

General circle form for any indicating instrument, with a placeholder replaced by the unit or quantity measured.

## In plain English

### What does Indicating instrument general mean?

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.

### A simple example

Because the placeholder carries all of the meaning, an unfilled general symbol tells the reader only that some reading is shown at that point. The drawing must still state the measuring connection, scaling from instrument transformers and whether the instrument is analogue or part of a digital meter.

### What the drawings help you do

Replace the placeholder with the actual unit before issue. Read the circle together with its measuring connections. The circle is the indicating form; recording instruments use a square and integrating instruments use a rectangle with a band.

### This particular reference

General circle form for any indicating instrument, with a placeholder replaced by the unit or quantity measured. The circle is the indicating form; recording instruments use a square and integrating instruments use a rectangle with a band.

### Terms

- Winding: A coil of conductor inside an electrical machine or transformer.
- Terminal: An identified point where a conductor connects.
- Schematic: A drawing showing function and connections rather than physical appearance.

Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference
A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/)
- [AutoCAD Electrical: Instrumentation and sensors](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-773A36C3-44C6-43EB-9BD0-E0297816B9B2.htm)


## What it represents

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.
Because the placeholder carries all of the meaning, an unfilled general symbol tells the reader only that some reading is shown at that point. The drawing must still state the measuring connection, scaling from instrument transformers and whether the instrument is analogue or part of a digital meter.

## How to read it

- Replace the placeholder with the actual unit before issue.
- Read the circle together with its measuring connections.

## Information to show or reference

- Fill in the measured quantity
- Show instrument transformer ratios
- List the instrument in the schedule

## Important distinction

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

## Facts

- Shape convention: Circle, placeholder replaced by unit
- Family: Indicating instruments
- Preview: Independent educational concept; consult the applicable standard and project legend for the exact graphic

## Public references

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/) — IEC. IEC context for graphical symbols used in diagrams; no IEC graphic is reproduced.
- [AutoCAD Electrical: Instrumentation and sensors](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-773A36C3-44C6-43EB-9BD0-E0297816B9B2.htm) — Autodesk. Public AutoCAD Electrical listing of instrument symbols built on the indicating form.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.