Measuring current requires a sensor that can detect Alternating (AC) or Direct (DC) current in a wire. Current is measured in Amperes (Amps) and can be displayed on a handheld device called an Ammeter (typically a multimeter). It can of course be recorded over time using a datalogger or used for control purposes.

Current Transducer Devices (CTD) provide a non-intrusive way to detect current flowing through cables and wires and can be used to monitor current loads, runtime status or proof of operation.