"PURPOSE This test is intended to evaluate in an accelerated manner@ the resistance of component parts to deterioration resulting from high humidity and heat conditions typical of tropical environments. This test differs from the steady-state humidity test (Method i)@ deriving added effectiveness from temperature cycling. This provides alternate periods of condensation and drying essential to the development of corrosion process@ and in addition produces a ""breathing"" of moisture vapor into partially-sealed containers. The test provides a time during which optional low temperature or vibration subcycles may be inserted for revealing the otherwise undiscernible evidences of deterioration."