The Hioki PW3360-20-01/500 Clamp On Power Meter with CT9661 Clamp Sensor set is a multi-channel power measuring device utilizing clamp sensor input to accurately and safely measure power on single-phase to three-phase lines. The PW3360-20-01/500 compact 3-Phase 4-Wire energy logger monitors power demand and other power parameters to aid in energy audits and validate energy saving measures.