A high voltage calibration method using the measuring spark gap

Spark gap use as a measuring system is still accepted by the international standards, in certain cases being an alternative for measuring circuit calibration. High voltage (HV) measurement is based on the experimental results of the calibrations carried out by several international laboratories and on the knowledge of correction factors corresponding to the atmospheric conditions during the test. The paper presents an updating of the process for atmospheric conditions measurement and for automatic determination of the spacing necessary to calibrate a voltage by means of the spark gap. Using the least squares method the analytical expression was determined under the form of interpolating polynomials for different voltage and sphere diameter types