Definition
An electrical instrument that measures small electric currents, calibrated in milliamperes (thousandths of an ampere). It is wired in series with the circuit being measured so that the current flows through it.
Plain English
A meter that shows how much electric current is flowing in a circuit, measured in very small units called milliamps.
Context Anchor
Seen in aircraft electrical system checks, instrument troubleshooting, and powerplant maintenance procedures where very small current flow must be measured.
Derivation
From 'milli-' (Latin mille, meaning thousand, used to indicate one-thousandth) + 'ampere' (the unit of electric current, named after French physicist André-Marie Ampère) + 'meter' (a measuring device). So a milliammeter measures current in thousandths of an amp.
Why Pilots Care
Small current readings often indicate the health of avionics, charging systems, and sensitive circuits. A milliammeter shows fine variations that a standard ammeter would miss, helping technicians spot trouble early.
Intuition Check
A milliammeter is not just any current meter. It is specifically for small current values measured in thousandths of an ampere.
Example Sentence 1
The technician connected a milliammeter in series with the circuit to verify the current draw was within specification.
Example Sentence 2
A steady milliammeter reading helped confirm the alternator control circuit was operating normally.