What does an ammeter measure in an aircraft?

An ammeter is a specialized instrument used to measure the flow of electric current in a circuit, typically expressed in amperes. In the context of an aircraft, the ammeter specifically measures the battery's charging and discharging current. This provides vital information regarding the battery's state of charge, helping pilots ensure that the electrical system is functioning properly and that the battery has sufficient power to operate critical systems.

The significance of this measurement can’t be understated; a well-functioning battery is crucial for powering avionics, lights, and other essential electrical systems on the aircraft. It allows pilots to monitor whether the electrical system is generating the power needed or if the battery is being depleted, thus preventing potential electrical failures during flight.