| 摘要 |
<p>PROBLEM TO BE SOLVED: To measure voltage in a no contact manner with a simple operation without measuring stray capacitance by eliminating the influence of the stray capacitance. SOLUTION: In this method for measuring an AC voltage Ex applied to a conductor which is in no contact by use of a detecting probe 11 comprising a detecting electrode 111 for partially covering the surface of an insulating material covering a conductor CD and a shield electrode 112 for covering the detecting electrode and an oscillator 12 for outputting a signal of prescribed frequency, one-side ends of the core wire and covered wire of a shield cable CV are connected to the detection electrode and shield electrode, respectively, and the other end thereof are turned into an imaginary short state, whereby the influence of stray capacitance is set substantially to zero. The signal of the oscillator is applied to the detecting electrode via the shielded cable in this state, whereby the impedance between the detecting electrode and the conductor is measured, an current Ix running out from the detecting electrode resulted from the voltage Ex is measured, and the voltage Ex is determined, on the basis of the impedance Zw and the current Ix.</p> |
