Measuring instrument for measuring the charging voltage and the stored electrostatic energy in electrostatic charges

摘要

The invention relates to a measuring instrument for simultaneously measuring the charging voltage with sign and the stored electrostatic energy in electrostatic charges. The electrical charges stored on a charged object are transferred via a discharging resistor to a capacitor of known capacitance which is initially discharged or charged to a known voltage. The voltage across this capacitor is measured several times during the charge transfer. From the measurement results, the voltage of the charged object at the beginning of the measuring process and the electrostatic energy stored on the object is automatically calculated by means of an analog or digital method. In one possible implementation, the electrical voltage across the capacitor contained in the measuring instrument is measured with an amplifier having a high input impedance. In another possible implementation, this capacitor has a piezoceramic dielectric which changes its dimension transversely to the direction of the electrical field when the electrical charges are applied to the capacitor foils. The change in length of the dielectric and thus the electrical voltage across the foils is measured with strain gauges. <IMAGE>