You can monitor an ac electrical line by routing a cable through the hole of the CS10.

The CS10 sensor consists of a CR Magnetic's CR8459 Current Transformer encapsulated in epoxy. It measures ac electrical current over a 0 to 200 Ampere range with an accuracy of ±10% of actual value. The CS10 outputs a millivolt signal allowing it to be directly connected to our dataloggers. Common applications include efficiency studies, intermittent fault detection, rough submetering, and monitoring motor or generator load conditions.