DISCHARGE TUBE WITH COATING MATERIAL APPLIED ON DISCHARGE SURFACE

摘要

A discharge tube (10) comprising two electrodes (14a and 14b) opposed to each other via intervening insulators (12), wherein the discharge surfaces of the electrodes (14a and 14b) are each coated with a coating agent (16) containing 0.01-60 wt.% of at least one alkali metal salt selected among potassium bromide, potassium fluoride and sodium fluoride in order to attain a stable starting voltage even under a surge voltage with a short rise time.