This part of IEC 60794 defines test procedures used in establishing uniform requirements for the environmental performance of " optical fibre cables for use with telecommunication equipment and devices employing similar techniques, and " cables having a combination of both optical fibres and electrical conductors. Throughout this document, the wording "optical cable" can also include optical fibre units, microduct fibre units, etc. This document defines a test standard to determine the ability of optical cable elements from a cable exposed in a mid-span entry (expressed) and stored in a pedestal, closure or similar to withstand the effects of temperature cycling by observing changes in attenuation. The optical cable element bundles up single or multiple optical fibres, e.g. loose tube, tight buffer tube, or optical fibre ribbon. See IEC 60794-1-2 for a reference guide to test methods of all types and for general requirements and definitions.