The impedance and its inverse, admittance, of nitrogen rf glow discharge are measured with an operating impedance bridge in two geometrically similar, radial-flow, parallel-plate plasma reactors. Separation of these electrical parameters into their constituents, resistance and capacitive reactance for impedance and conductance and susceptance for admittance, permits an evaluation of the electrical behavior of these discharges. At power levels between 0.06 and 0.4 W/cm2 and electrode spacings between 2.5 and 8.2 cm, the discharge conductance generally increases with rf power and electrode spacing. However, the exact trends depend upon the specific reactor. Based upon these results, an electrical similarity criterion is proposed that may assist transfer of plasma etching and deposition processes from one reactor to another.