Abstract
Discontinuities in the slopes of Langmuir probe characteristics for discharges in mercury vapor in the presence of argon or krypton gas were eliminated by heating the wire probe by electron bombardment before each reading. The results indicate that in many cases nonlinear probe plots are due to change in the contact potential of the probe and do not mean a non‐maxwellian distribution of electron velocities. Typical probe plots are given for discharges with and without striations, and also for a discharge in gas contaminated by a trace of CO or CO2. Electron temperature data are listed for representative pressures of gas and mercury vapor and for various discharge currents.