Abstract
The impedance method is extended to deduce simple and convenient formulas for measuring electron density higher than the critical value corresponding to the plasma resonance. The determination of both the electron density and the collision frequency in transient plasmas is possible by simultaneously recording two detected microwave signals. The electron density range measurable covers from 1×1013 cm-3 to 5×1010 cm-3, at a frequency of 9000 mc/sec.