Ammeter
A measurement instrument that displays the current flowing through it. Must be placed in series with the branch you want to measure — the ammeter becomes part of the current path.
Properties
| Property | Description | Default | Range |
|---|---|---|---|
| Internal resistance | Series resistance introduced by the meter (Ω) | 0.01 Ω | 0.001 Ω – 10 Ω |
| Range | Maximum current that can be displayed (A) | Auto | 1 mA / 100 mA / 1 A / 10 A / Auto |
| Display precision | Number of decimal places shown on the readout | 3 | 1 – 6 |
Simulation behavior
During simulation the ammeter displays the instantaneous current through its terminals in real time. The reading updates on every solver tick.
If range is set to a fixed value and the actual current exceeds it, the display shows OVR (overrange). In Auto mode the range adjusts automatically and the unit prefix scales (µA, mA, A).
The small internal resistance is included in the circuit model. For most circuits 0.01 Ω is negligible, but it matters in very low-resistance or high-current branches.
Tips
- Break a wire and insert the ammeter in the gap to measure current in a specific branch — do not place it in parallel, which would short-circuit the branch.
- Set a fixed range when you already know the expected current order of magnitude to get a more stable, readable display.
- Add multiple ammeters at different points in a parallel circuit to verify Kirchhoff's Current Law: the sum of branch currents equals the total current.