An amperemeter is another name for an ammeter.
Hans Christian Ørsted
An ammeter is commonly used to detect electron flow in a circuit. The ammeter measures the amount of current (flow of electrons) passing through a specific point in the circuit.
An ammeter either directly, or via a current transformer, is used to measure current in a circuit.Current transformers (CTs) are necessary when either (1) you need to measure the large currents flowing in high-voltagesystems (a CT will isolate the HV system from the ammeter to which it is connected, as well as reduce the value of the HV current) or (2) you need to reduce the very large currents to be measured in medium-voltage systems.