The purpose of this part of IEC 61300 is to describe a test to determine the suitability of a fibre
optic device to withstand the environmental condition of high humidity and change of
temperature which can occur in actual use, storage and/or transport.
The test is primarily intended to determine the suitability of fibre optic components under
conditions of high humidity – combined with cyclic temperature changes and, in general,
producing condensation on the surface of the device under test (DUT). Absorption of moisture
can result in swelling that would destroy functional utility, cause loss of physical strength, and
cause changes in other important mechanical properties. Degradation of optical properties can
also occur.
Although not necessarily intended as a simulated tropical test, this test can, nevertheless, be
useful in determining moisture absorption of insulating or covering materials.