Based on Faraday electromagnetic induction principle, HCT series sensors adopt selfintegration mode, without additional power supply, and realize current detection in an ultrawide frequency range. The sensor is connected to the voltage measuring instrument with 50 Ω coaxial cable, such as oscilloscope, spectrum/network analyzer, voltmeter and digitizer. Standard connectors include BNC, SMA, UHF or N-type connectors. The wire must be fully insulated because the conductive housing of the sensor is painted, but there is no other insulation. Corresponding electrical isolation or safety grounding is required during use.