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/ˈæmɪtɚ/
🇺🇸
/ˈæmɪtɚ/
🇬🇧
/ˈæmɪtər/
🇬🇧
/ˈæmɪtər/
Plural
ammeters
An ammeter is a device that measures how much electric current—expressed in amperes—is flowing through a circuit. Think of it like a 'traffic counter' for electrons: just as you'd count cars passing a point on a highway, an ammeter counts the flow of charge per second—and it must be wired *in series* with the circuit to do its job correctly.
Always connect the ammeter in series with the circuit, not in parallel, or you risk damaging the instrument.
The technician checked the faulty motor by attaching an ammeter to its power line.
Modern digital ammeters display current readings with high precision and minimal interference to the circuit.
When the ammeter showed zero current, we realized the fuse had blown.
Students learned to use both analog and digital ammeters during the electricity lab.
amper
Comes from the name of French physicist André-Marie Ampère (1775–1836), after whom the SI unit of electric current—the ampere—is named. The root 'amper-' denotes electrical current measurement and is used in technical terms related to amperes. Examples include ammeter, ampere, amp (colloquial short form), and amperage.
meter
Comes from the Greek noun 'metron' (μέτρον), meaning 'measure' or 'measuring device'. It entered English via Latin and French, and forms the second element in many scientific instruments that measure physical quantities. Examples include thermometer, barometer, voltmeter, ohmmeter, and speedometer.