This Standard recommends and describes methods of measurement of the important electrical characteristics of semiconductor diodes. For the purpose of this Standard, a semiconductor diode is defined1 as: A semiconductor device having two terminals and exhibiting a nonlinear voltage--current characteristic; in more restricted usage, a semiconductor device which has the asymmetrical voltage--current characteristic exemplified by a single p-n junction. Methods of test are described for static, small-signal and pulse parameters. Many of the terms considered herein have been set down in AI E E and IRE Standards, particularly in 60 IRE 28.SH and AI EE No. 4252.