Definition
A handheld electrical test instrument that measures multiple electrical quantities, typically voltage, current, and resistance, and displays the readings on either an analog needle scale or a digital screen.
Plain English
A small electrical tester that can check voltage, current, or resistance, depending on which setting you select. One tool, several jobs.
Context Anchor
Seen during aircraft electrical troubleshooting, wiring checks, battery checks, and maintenance inspections.
Derivation
From 'multi-' (Latin multus, meaning 'many') plus 'meter' (Greek metron, meaning 'measure'). Literally a 'many-measure' device — one instrument that measures several different electrical values instead of needing a separate meter for each.
Why Pilots Care
Maintenance technicians rely on a multimeter to find faults in aircraft wiring, confirm bus voltages, and verify continuity in circuits before signing off work. A correct reading on the right setting can be the difference between catching a fault on the ground and discovering it in flight.
Analogy
A multimeter is like a basic health-check tool for an electrical system: it does not fix the problem by itself, but it helps show what is present, missing, or interrupted.
Example Sentence 1
The technician used a multimeter to check the voltage at the battery terminals before installing the new battery.
Example Sentence 2
To diagnose the avionics power issue, check the bus voltage with a multimeter set to DC volts.