amperometri

An amperometer, or ammeter, is an instrument used to measure the electric current in a circuit. In typical configurations, it is connected in series so that the same current flows through it as through the circuit. The basic device converts electrical current into a readable signal, often a deflection of a needle or a digital value, calibrated in amperes.

The design has two main approaches: high-sensitivity meters use a galvanometer with a low-impedance shunt to handle large currents, while modern digital amometers use electronic sense circuits with shunt resistors or current transformers to minimize burden voltage on the circuit. Burden voltage—the voltage drop across the meter—must be small to avoid perturbing the circuit.

There are several types: direct-current ammeters (DC), AC ammeters, shunt-type ammeters for high currents, clamp meters that sense current without breaking the circuit, and digital meters with display. Some instruments also function as panel meters, multi-range devices, or integrated in multimeters.

History and naming: the device originates from the galvanometer and is historically linked to the unit of electric current, the ampere, named after André-Marie Ampère. Ammeters have evolved from mechanical motion to solid-state electronics, enabling higher accuracy, wider ranges, and safe measurement in power systems.

See also: Ammeter, galvanometer, shunt resistor, clamp meter, multimeter.