The frequency response to alternating current of a fine wire surrounded by alkali metal vapor was studied theoretically and experimentally for determining the thermal conductivity of the vapor. Data were obtained for cesium and rubidium vapors at pressures from 0.0829 to 0.214 atm. A new method was employed of correcting for temperature jump and vapor volumetric heat capacity.
The reliability of the method is indicated by agreement with literature values for argon up to 1,085 ℃. The standard error of the argon correlation is estimated at 1.6 %, and the total probable experimental error in the cesium and rubidium vapor measurements is estimated at 5.1 %.