Temperature effects in glow-discharge tubes

Glow-discharge reference tubes with various cathode materials, but identical gas filling and pressure, operating in the normal-glow mode, show different temperature coefficients when operated under similar conditions. Measured temperature coefficients are compared with calculated values obtained from a knowledge of the running-voltage/current characteristics at different pressures and temperatures. An existing theory is shown to hold for all the combinations of gas filling, geometrical construction and cathode material examined, and the differences in temperature coefficients are attributed to the uniqueness of the running-voltage/pressure curve for each particular gas-filling/cathode-material combination. A theory is proposed which enables the temperature coefficient of a tube operated with anode fall to be estimated from a knowledge of the running-voltage/current characteristic at different pressures and temperatures. Good agreement was obtained between measured and calculated values.