Definition
An electrical instrument used to measure very small electric currents, with a scale calibrated in microamperes (millionths of an ampere).
Plain English
A meter that measures extremely tiny electrical currents — currents far too small to register on a regular ammeter.
Context Anchor
Seen in aircraft electrical maintenance, instrument testing, and troubleshooting of low-current circuits.
Derivation
Built from three parts: 'micro-' (Greek mikros, meaning small) used here to mean one-millionth, 'amp' (short for ampere, the unit of electric current, named after French physicist André-Marie Ampère), and '-meter' (Greek metron, measure). So literally: a device that measures millionths of an amp.
Why Pilots Care
Allows precise verification of low-current signals in navigation, communication, and sensor circuits without risking damage to sensitive components.
Intuition Check
Do not read microammeter as just another name for any electrical tester. It specifically measures very small electric current, not voltage or resistance.
Example Sentence 1
The technician used a microammeter to measure the small current flowing through the VOR receiver's output circuit.
Example Sentence 2
During the electrical inspection, the microammeter showed a steady reading of 45 microamperes through the indicator circuit.