As part of its Category 8 Cable Testing information library, Fluke Networks produced a white paper covering shield integrity—a term that may be new to many cabling technicians. The brief document opens by explaining, “Field testing of screened cabling systems has always required that the tester verify there is continuity of the screen to the remote end of the test.” It cautions, however, that some field testers can incorrectly report screen continuity, thereby failing to highlight potential problems with the cabling system.
The document uses illustrative examples to show that there are three main paths through which an installed cabling system can achieve a simple electrical connection between the screen contacts of the near-end and remote testers. But “only one of those paths assures correctly terminated cabling that will allow the cable to function the way it is designed to.” Specifically, under certain scenarios some testers can incorrectly report that screen continuity has been achieved because those testers do not test continuity along the path of the cabling.
Fluke Networks points to using standard-compliant test instruments as a means of assuring accurate screen-continuity reporting. “Testing of the screen continuity has always been specified by the field tester standards, TIA-1152 and IEC 61935-1,” the company points out, adding, “however no guidance was given to specify the path through which that continuity was provided.
“For the first time, this has been addressed in TIA-1152-A, which provides a clarification of this screen testing requirement for Level 2G testers that must be used to test Category 8 cabling.”
The document quotes Clause 4.2.2 of TIA-1152-A: “In addition, for Level 2G testers it is understood that the screen continuity is tested along the path of the cabling.”
Fluke Networks makes the white paper available to anyone who provides their contact information. You can download the paper here.