On the Free Potential of the Grid and Plate of the Triode Valve and the Apparent Distr ibution of the Initial Velocity of Electrons

Abstract

The free potential of the grid and plate of the triode valve was measured by means of a quadrant electrometer. The free potential of the grid was found to be negative in most cases even if the plate voltage is kept high by external source of E. M. F. The effect of grid leak on the free potential of the grid was studied in detail and from this result the apparent distribution of the initial velocity of electrons was calculated.
The capacity of the quadrant electrometer was measured by beat method using a triode valve audio-frequency oscillator. From this value of capacity, the leakage of the quadrant electrometer and the triode valve was determined by time constant method. The time constant of the discharge of the quadrant electrometer was increased when the grid is connected to the electrometer and the valve was filled with electrons by heating the filament previously. This is due to the space charge which gradually accumulate to the grid and discharge through the leak. By this conception the equivalent electrostatic capacity of the vacuum space of the valve was determined. (April, 1923).