An ammeter is an electrical instrument used to measure the flow of electric current in a circuit. The current is measured in amperes (A), which is the unit of electric current in the International System of Units (SI).
Key Features of an Ammeter:
- Function: Measures the magnitude of current flowing through a circuit.
- Connection: Always connected in series with the circuit so the current flows through the device.
- Types:
- Analog Ammeter: Uses a needle or pointer to display the current on a scale.
- Digital Ammeter: Displays the current value numerically on a digital screen.
- Range: Can measure currents ranging from microamperes (μA) to kiloamperes (kA), depending on the design.
- Internal Resistance: Designed to have very low internal resistance to minimize the voltage drop across it and ensure accurate measurements.
Applications:
- Monitoring current in electrical circuits.
- Troubleshooting electrical and electronic devices.
- Ensuring safety by checking current levels in power systems.
Ammeter variants include clamp meters, used to measure current without breaking the circuit, and shunt ammeters, used for high-current applications.