The Ammeter recoerder uses the same sensor technology as the original Rogowski coil. The True RMS inductive sensor does not use magnetic materials. The opening of the sensor is electronically closed and external currents are electronically rejected.The accuracy, external current reject, and range of currents measured by the patented amp sensor substantially exceed the performance of the best clamp-on sensors. The key feature of the unit is the ability to leave it deployed on the line to record readings every 15 minutes for 90+ days. It easily attaches to the line with a standard insulating bar. Once on the line, it immediately begins to collect and record the primary current on the line.The Wireless Currrent Load Logger is equipped with a 433M wireless port for communicating the recorded data into the user's PC. The data is downloaded through GF2018S PC-Link Software, which allows the user to download, view and query the data stored on the Primary current recorder. it can analysis load growth, three phase unballance, power quality in medium voltage overhead power line.