A new life-quality measure for electron tubes

Since the Military Standard MIL-E-1B replaced JAN-1A Specifications, the tube industry and tube users have been searching for a common satisfactory measure for the life quality of electron tubes. This paper proposes a new measure, incorporating the information in the electron tube failure-age distribution for replacement of the obsolete Average Life Percentage originally specified in JAN-1A. A Weibull distribution with a fixed shape parameter was found appropriate for describing the failure age of electron tubes under a wide variety of application. Hence, a single measure, the scale parameter, will characterize the life quality of electron tubes. Secondary life-quality measures, such as mean life, median life and the recently introduced “reliability,” hazard rate, etc., can all be expressed in terms of the proposed measure. Some numerical examples are given at the end of the paper.