Coupling Attenuation is to be an optional in-field test for installation conformance testing

Coupling Attenuation is to be an optional in-field test for installation conformance testing

While it is possible, it will not be a perfect fit.

The intended inclusion of coupling attention for shielded and unshielded cabling as an optional in-field test for installation conformance to ISO/IEC 11801 (AS/NZS 3080) and IEC 61935-1 (Tester standard) presents a number of challenges.

At present, the testing for coupling attenuation is restricted to laboratory testing of shielded connectors and shielded cables in channel assemblies.

Traditionally, additional test requirements would be achievable provided appropriate test equipment was available to the installers and the expectation that the installers would have adequate trained staff to undertake and interpret the testing.

This would certainly be true for alien crosstalk, DC resistance unbalanced-between pairs and DC resistance unbalanced-within a pair testing.

The latest field testers as yet, do not address coupling attenuation.

The test methods associated with the ongoing development of IEC 61935-1 address the testing of coupling attenuation by use of a laboratory network analyser and (luggable) artefacts. The use of this equipment and the test methodologies would be better suited to remain with laboratory based engineers.

The rectification strategy for addressing failure of coupling attenuation in the field appears to be based primarily on recabling of the installation. This would not be a suitable risk strategy to meet project program delivery obligations.

The JTC1 SC25 WG3 meeting in Singapore confirmed coupling attenuation as a field test of ISO/IEC 11801 and rejected any additional information being provided to inform the reader of the complexity of the test.

The question is, what is the intent of coupling attenuation testing in the field.

Outside of being a method of qualifying lower performing components used in the creation of say a mixed product channel, it is hard to see the benefit of coupling attenuation testing of installed cabling.

The need for specialised equipment and personnel seems to add significant cost and complexity while delivering no tangible benefits

While coupling attenuation will be an optional installation conformance in-field test, it would be hard to recommend its inclusion against any risk modelling and even harder to justify the additional time and equipment expense to installers along with the subsequent on cost to the client.

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