# Galvanometer

Canonical URL: https://eloragrid.ai/symbols/galvanometer
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: G
Drawing use: Schematic
Reference families: IEC, IEEE / ANSI

Sensitive indicating instrument used to detect very small currents or a balance point in a bridge circuit.

## In plain English

### What does Galvanometer mean?

A galvanometer is a very sensitive current indicator, often with a centre zero, used to detect small currents rather than measure them to a scale. It is drawn in bridge and comparison circuits, where the operator adjusts a component until the galvanometer reads zero.

### A simple example

On modern drawings the function is often performed by an electronic null detector, but the symbol still marks the balance point. It does not show sensitivity, damping or protection against overload, which matter because the instrument is easily damaged by currents far above its scale.

### What the drawings help you do

Identify the two points whose balance is being detected. Look for protective shunts or switches around the instrument. A galvanometer detects small or zero current; an ammeter measures current to a calibrated scale.

### This particular reference

Sensitive indicating instrument used to detect very small currents or a balance point in a bridge circuit. A galvanometer detects small or zero current; an ammeter measures current to a calibrated scale.

### Terms

- Rating: A value stating the conditions for which equipment is specified.
- 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/)
- [IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams](https://standards.ieee.org/ieee/315/515/)


## What it represents

A galvanometer is a very sensitive current indicator, often with a centre zero, used to detect small currents rather than measure them to a scale. It is drawn in bridge and comparison circuits, where the operator adjusts a component until the galvanometer reads zero.
On modern drawings the function is often performed by an electronic null detector, but the symbol still marks the balance point. It does not show sensitivity, damping or protection against overload, which matter because the instrument is easily damaged by currents far above its scale.

## How to read it

- Identify the two points whose balance is being detected.
- Look for protective shunts or switches around the instrument.

## Information to show or reference

- State sensitivity
- Show protective shunt
- Identify bridge arms

## Important distinction

A galvanometer detects small or zero current; an ammeter measures current to a calibrated scale.

## Facts

- Typical use: Bridge balance and null detection
- Scale: Often centre-zero
- 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.
- [IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams](https://standards.ieee.org/ieee/315/515/) — IEEE Standards Association. Graphic-symbol standards context for instrument designations.

## 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.