Ionization Potentials of Argon, Nitrogen, Carbon Monoxide, Helium, Hydrogen and Mercury and Iodine Vapors

Measurement of the Ionization potential of Gases was accomplished by means of a two electrode tube, by determining the point on the current-voltage curve at which the current increases at a rate faster than that given by Langmuir's equation $i=A{(V+V_0)}^{\frac{3}{2}}.$