What instrument is used to measure electrical current?

Electrical current is the rate at which electrons flow past a point in a complete electrical circuit, and it is measured in amperes (amps). The instrument specifically designed to measure this flow is called an ammeter. To use an ammeter, it must be placed in series with the circuit so that the current physically flows through the meter. A voltmeter, by contrast, is placed in parallel to measure voltage, while a wattmeter measures power and a wavemeter measures radio frequencies.