A current sensor measures electric current flowing through a conductor or circuit. Depending on its design, it may measure current directly or detect the magnetic field produced by current. Sensors vary in accuracy, isolation, response speed, and how much they affect the circuit being monitored.
In cyber security, current sensors can help monitor power use in devices, detect abnormal loads, and support hardware diagnostics. Unexpected changes in current may indicate a fault or suspicious activity, but readings must be interpreted in context. Sensor noise, measurement limits, and interference from the device itself can affect results, so monitoring systems should combine current data with other signals where possible.