This part of IEC 61300 details a procedure for determining the suitability of a fibre optic
device to withstand the environmental condition of high humidity and high temperature which
may occur in actual use, storage and/or transport. The test is primarily intended to permit the
observation of effects of high humidity at constant temperature over a given period.
Absorption of moisture may 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 may 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.