The Relationship between the Emission Constant and the Apparent Work Function for Various Oxide-Coated Cathodes

Measurements were made of the emission of oxide-coated cathodes on six chemically different metal wires over a period of 500 hours. An empirical emission equation was employed which was found to be as accurate as the conventional Dushman equation and to be simpler to use. It was found that the logarithm of the emission constant A′ varied as the sum of the apparent work function times a constant, and the constant B.