Non-invasive AC Current sensors are likely to be used in power monitoring and current metering. This sensors take advantages on the magnetic field induced by flowing current and using magnetic circuits, it transforms the flowing current to a lower one which is possible to meter by low voltage devices.
The use principle is as simple as putting the wire inside the core and connect it to a resistor and measure the current. Applying Ohm to the voltage in the resistor, you will be able to get the flowing current multiplying it by a scale factor, given by the sensor.
Hole size: 13mm