  This paper proposes a method for studying the early stages of the cavitation
development in arbitrary, non-stationary conditions. This method is based on
the comparison of the results of calculations in the framework of a theoretical
model of the liquid dielectrics motion in a strong non-uniform electric field
and experiments with controlled parameters. This approach allows us to find the
critical negative pressure, at which cavitation begins to develop, and to
determine the values of the constants in the classical models of cavitation.
