Evaluating the Ignition Sensitivity of Thermal-Battery Heat Pellets

Abstract

Thermal batteries are activated by the ignition of heat pellets. If the heat pellets are not sensitive enough to the ignition stimulus, the thermal battery will not activate, resulting in a dud. Thus, to assure reliable thermal batteries, it is important to demonstrate that the pellets have satisfactory ignition sensitivity by testing multiple specimens. There are many statistical methods for evaluating the sensitivity of a device to some stimulus. Generally, these methods are applicable to the situation in which a single test is destructive to the specimen being tested, independent of the outcome of the test. In the case of thermal-battery heat pellets, however, tests that result in a nonresponse do not totally degrade the specimen. This peculiarity provides opportunities to efficiently evaluate the ignition sensitivity of heat pellets. In this article, a simple strategy for evaluating heat-pellet ignition sensitivity (including experimental design and data analysis) is described. The relatively good asymptotic and smallsample efficiencies of this strategy are demonstrated.