Electrical discharge machining (debris) to be carried away and the insulating properties of the dielectric to be restored. Adding new liquid dielectric in the inter-electrode volume is commonly referred to as "flushing." Also, after a current flow, the difference of potential between the electrodes is restored to what it was before the breakdown, so that a new liquid dielectric breakdown can occur. The erosive effect of electrical discharges was first noted in 1770 by English physicist Joseph Priestley. Two Russian scientists, B. R. Lazarenko and N. I. Lazarenko, were tasked in 1943 to investigate ways of preventing the erosion of tungsten electrical contacts
International System of Electrical and Magnetic Units and Measures (CIPM) approved a new set of definitions for electrical units, based on the rationalized MKSA system, in 1946, and these were internationally adopted under the Metre Convention by the 9th General Conference on Weights and Measures in 1948. Under this system, which would become the International System of Units (SI), the ohm is a derived unit. The SI definitions of the electrical units are formally equivalent to the 1908 international definitions, and so there should not have been any change in the size of the units. Nevertheless, the international ohm and the international volt were not usually realized