Patent ID: 6825649
Filing Date: 2004-11-30
Classification: G01R

Abstract:
A non-contact voltage measurement method for measuring an AC voltage applied to a conductor, without contacting the conductor, using a detection probe, provided with a detection electrode capable of covering part of a surface of insulation for insulating the conductor and a shield electrode for covering the detection electrode, and an oscillator for outputting a signal having a certain frequency, whereinone end of each of a core wire and a sheath wire of a shield cable are connected to the detection electrode and the shield electrode, and a floating capacitance effect is substantially made zero by establishing an imaginary short-circuit state between each of the other ends, comprising the steps of: measuring impedance between the detection electrode and the conductor by applying the signal from the oscillator to the detection electrode via the shield cable; measuring a current discharged from the detection electrode attributable to a voltage applied to the conductor; and obtaining the voltage applied to the conductor based on the measured impedance and the measured current.