Observations on corona in restricted gaps

The absolute magnitude of the coulomb or electron charge in a corona pulse can be obtained from a measurement of the instantaneous voltage change produced by the pulse on the device, or test piece. This voltage, ΔV, is most easily measured by measuring the maximum amplitude of the damped high frequency oscillation generated across a small inductor connected in series with the test piece showing corona. The charge in the pulse is given by Q = C Δ V, where C is the effective capacitance across which the Δ V appears.