abstract:The highly accelerated stress test (HAST) method was invented by Nihal Sinnadurai while working as a Research Engineer at British Telecommunications Research Laboratories in 1968 in order to perform highly accelerated reliability testing of electronics components that are likely to encounter humid environments during normal (ambient) operation. The method uses the principle of a non-saturating autoclave designed and engineered with no moving parts, to deliver close temperature (AF_{H} = e^{(Constant*(RH_{s}^n-RH_{o}^n)}