TIA ANSI/TIA/EIA-455-73

Introduction

This test procedure describes a method for the determination, in an accelerated manner, of the effects of temperature and humidity cycling on the mechanical characteristics of optical fibers. It is intended to assess the ability of an optical fiber to withstand cyclic changes in temperature and humidity in the surrounding atmosphere. The performance of the fiber during and after cycling may be evaluated be performing specific mechanical tests.

The specification of this procedure in conjunction with defined failure criteria presupposes that the failure criteria selected to evaluate the property or properties being measured as a function of the cycling conditions and duration can be shown to relate to the intended use of the optical fiber. At the time this document was prepared, no proven model existed for the prediction of the lifetime performance of fiber deployed in field applications using date generated through cyclic temperature and humidity testing.

Optical fibers exposed to temperature and humidity cycling may be subject to many types of changes. The severity of the exposures in time, temperature, and humidity determines the type and extent of change. A mechanical property may not necessarily be degraded by such cyclic exposure, but may remain unchanged or even improve. A typical indication of damage resulting from such cycling is an excessive temporary or permanent change in a mechanical property, such as the fiber strength. The degree of change observed will depend on the specific property measured. Different properties may not change at the same rate, and the rate and direction of change may not be constant over time, temperature, and humidity.

The effects of exposure may be quite variable, especially when specimens are exposed for long time intervals. Reproducibility is affected by the temperature and humidity control tolerances, the duration of the exposure, and the aging characteristics of the fiber coating(s), among other factors. Errors in exposure conditions may have cumulative effects over time.

This test is destructive; the fiber specimens are not expected to remain usable after completion of the test.