Method for calibrating charge density in space charge distribution measurement

摘要

PROBLEM TO BE SOLVED: To provide a calibration method of electric charge density in a space-charge distribution measurement capable of highly accurately performing calibration even when a space charge is generated by application of a DC voltage when calibrating the electric charge density in the space-charge distribution measurement of the inside of an insulation material.SOLUTION: The calibration method includes the steps of: when a voltage signal measured from a measurement sample 2 to which only a pulse voltage is applied, is defined as V1, a voltage signal measured from the measurement sample to which a pulse voltage is applied with a DC voltage applied thereto, is defined as V2, and, immediately after the step-down of the DC voltage, a voltage signal measured from the measurement sample 2 to which a pulse voltage is applied with it connected to ground, is defined as V3, acquiring a voltage signal V4 calculated by V2-V3+V1; and calibrating the charge density obtained from the voltage signal V2 using the voltage signal V4.