Active Standard ASTM F83 | Developed by Subcommittee: F01.03
Book of Standards Volume: 10.04
Historical (view previous versions of standard)
This practice covers the definition and interpretation of the commonly used thermionic constants of electron emitters with appended standard methods of measurement. Cathode materials shall alternatively be evaluated by relating the temperature-limited emission to fundamental properties of the emitter, particularly the work function. Comparisons are made between emitters using the thermionic constants such as the work function, emission constant, and the temperature dependence of the work function. These thermionic constants are geometry and field effects-independent, but exhibit variations under different conditions. The pertinent equations the Richardson-Dushman equation of electron emission to evaluate the effective work function, which in turn, shall be used to find the Richardson work function and the true work function. Sample computations are also detailed.
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2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
F8 Recommended Practice for Testing Electron Tube Materials Using Reference Triodes Withdrawn.
ICS Number Code 01.040.31 (Electronics (Vocabularies)); 31.100 (Electronic tubes)