2013 年 7 月 10 日 / Adrian Young / General
If you’re in the cable testing business, you should know about ETL Verification.
When it comes to cable certification devices, users are expected to trust the vendor and the accuracy claims they make. There is no practical way for the user to verify accuracy as it involves an expensive laboratory network analyzer, special fixtures and of course a technician who’s familiar with the intricacies of field testing standards such as ANSI/TIA-1152 and IEC 61935-1 ed 3.0.
The ETL Verification mark is designed to assure users that the test equipment meets the accuracy claims/requirements specified in the appropriate ANSI/TIA and IEC standards. Fluke Networks is the first test equipment vendor to obtain ETL Verification to draft Level V accuracy (1 GHz) with its recently unveiled DSX-5000 CableAnalyzer.
In the cabling industry, there is an expectation that your products should be ETL Verified – even if you have been producing field certification testers for more than 18 years, as is the case with Fluke Networks. Some contracts specifically call out a requirement for third party verification of accuracy.
To obtain an ETL Verification, an engineer from Intertek (ETL) will come to the manufacturers’ factory and randomly sample products from the production line. This is a deliberate and enforced process to avoid accusations of finely tuned test equipment being used for the verification process. Measurements are made on reference links using the randomly selected testers and the results compared to a laboratory vector network analyzer. Important additional measurements, such as directivity, are also verified against the field testing standard.
The ETL Verification program is part of an industry wide third-party verification program for field testers. Field testers typically have to be approved by the cabling vendor offering the warranty on the cabling system too. Before that approval begins in their labs, the cabling vendor will typically demand proof of a successful ETL Verification.
Navigating the field-testing standards can be daunting. For the field certification of Category 6A 500 MHz, the user must demand better than Level IIIe accuracy as found in ANSI/TIA-1152. The DSX-5000 CableAnalyzer has been verified to Level IIIe accuracy by Intertek (ETL).
In ISO/IEC 11801:2010, it’s a little more complicated. This standard supports links up to 1 GHz (Class FA), but its field testing standard IEC 61935-1 ed 3.0 only supports field testing to 600 MHz (Class F). As a result, the IEC group responsible for this standard has spent the past three years revising it to support field testing to 1 GHz (Class FA cabling systems). It’s still a draft and as such, not available to the public. Publication is not expected until next year. However, no more technical comments are expected between now and publication, so you should see other test equipment vendors apply for ETL Verification to this draft standard for Level V accuracy in support of 1 GHz field certification.
What does this ETL Verification mean for Fluke Networks’ customers? They can have absolute confidence that when they use the DSX-5000 CableAnalyzer, the measurements are solid and meet the field test standards for accuracy. In addition, they may also use the field tester where the contract calls out for third party verification of accuracy.