Cable testing

To get value for money from your cabling company, it's important to appreciate to difference between types of testing. A good cabling company will always provide Certification of your installed cabling system. This compares the performance of an installed cabling system to a standard because performance depends on component quality and installation workmanship.

Alternatives to certification are qualification and verification. Qualification confirms that the installed cabling links successfully transmit data using a specific network technology, Gigabit Ethernet for example, but does not imply compliance with technologies other than the one used in the test. Verification is a very simple test that just confirms the installed link meets basic continuity requirements. It does not imply any bandwidth or transmission quality measure.
Unless your after the cheapest installation possible, you should not accept anything less than certification with a instrument such a Fluke DTX.

Alan Bullen
Lynx Networks

Testing of Data Cabling

Here’s some excellent info to help you negotiate a good deal from your cabling installer and to make sure you get value for money.

There are three forms of testing data cabling:
Certification – Tests all parameters required by ratified standards and provides a certificate for each link or channel.
Qualification – Only tests the cabling to work for particular applications or network standards.
Verification – Tests only the most essential parameters.

Lynx Networks recommends certification testing for every link or channel. This should prove cost effective in the long term. It is condition of most manufacturers’ warranties that the cabling system is 100% certified.

For every installation where either certification or qualification testing is undertaken, complete individual test reports (or certificates where appropriate) configured in accordance with the agreed standard, should be included with the installation documentation. The format and material on which these reports are to be presented should form part of the contract. (See the Labelling, Records and Documentation section above).

Certification Testing of Data Cabling
Certification is carried out with a standards-compliant tester, such as a Fluke DTX, with the required accuracy for the Class or Category of cabling installed. You specify whether the cabling system is to be certified to BS EN50173 series of standards, ANSI/TIA/EIA 568-B series of standards or ISO/IEC 11801, although the choice of cabling system manufacturer may predetermine this.
By definition, certification testing includes qualification testing.

Qualification Testing of Data Cabling
For installations where a manufacturer warranty is not offered, qualification is a less stringent alternative to certification but it is important to note that qualification testing:
Uses less accurate test equipment to compare installed cabling performance with the requirements of specific applications.
Can only provide results for existing application standards.
Cannot provide any form of ‘future proofing’ as it deals only with existing applications.
Is limited to the ‘Channel’ test model, i.e. includes the equipment, patch and work area type cords.

Verification Testing of Data Cabling
This will eliminate common installation errors but will not guarantee that the cabling system will support the network or bandwidth requirements.
Minimum test and inspection for copper cabling
A visual inspection of the terminations
Wire-mapping test to confirm there are no open circuits, short circuits or crossed wires, including the cable screen if present. This will also confirm that telecommunication outlets and patch panels are identified and labelled correctly.
Plus, optionally:
Cable length
Test to ensure there are no split pairs.
For more information like this, go the www.lynxdatacabling.co.uk and download the free guide "Specifying an IT Cabling System".

Alan Bullen, Oct 2007.