METHOD FOR DETERMINING OXIDE CATHODE EMISSIVE ACTIVITY IN VACUUM TUBES Russian patent published in 1997 - IPC

FIELD: electronic engineering; vacuum-tube manufacturing process providing for viewing oxide cathode to determine its emissive activity. SUBSTANCE: voltage is applied between cathode and current-collecting electrode; then cathode oxide layer is exposed to light, whereupon cathode photoelectronic emission current is measured; during exposure to light, cathode is held at room temperature without heater voltage application to it. Emissive activity can be measured both in relative units and in terms of current density at any fixed power of photoexciting light flux. EFFECT: reduced labour consumption and improved measurement accuracy. 6 dwg