Then AESA introduces Cobalt, a new balunless automatic test equipment based on the modal decomposition mathematical algorithm. Cobalt helps the development of new cables (complete tests at the lab). It simplifies as well the operator’s tricky job within the systematic tests after production, essential to get reliable results.

Performance:

• Very broad frequency range (>4GHz)

• No more baluns used, so full dynamic available

• More than 170 parameters available including LCL family and in Pair skew

• Automatic LCL measurement

• Measurement of short length possible (10m), reduced scrap

• Perfect balance, common mode measurement integrated

• No movable parts requiring mechanical adjustments or periodical maintenance

• Exclusive High-Tech HF switching using MIL standardized relays

It is often difficult to overcome errors and instabilities while measuring the linear resistance of multi-strand cables and cords. It is demonstrated here that the main issue stems from inter-wires contact resistances. A new contacting method has been developed allowing mastering this metrological task.

Résumé

Il s’avère souvent ardu d’éliminer erreurs et instabilités lors de la mesure de résistance linéique de câbles ou de cordes multi-brins. Ce travail démontre que le problème principal est provoqué par les résistances de contact entre fils. Une nouvelle méthode de test a été développée pour maîtriser cette métrologie.

Zusammenfassung

Es erscheint oft nicht einfach Fehler und Instabilitäten bei der Messung von linearen Widerständen an Litzen zu vermeiden. Es wird hier gezeigt dass das Hauptproblem von den Kontaktwiderständen zwischen Adern stammt. Eine neue Messeinrichtung ist entwickelt worden um diese Messaufgabe zuverlässig zu meistern. 

Presentation Summary:

Tuesday, May 3, 2011

Electrical Session 1

10:30 am—11:00 am

« Effects of contact resistances in  multi-strand cables on linear resistance measurements » by Patrick De Bruyne and Gaël Mauron, AESA SA, Switzerland.

It is often difficult to overcome errors and instabilities while measuring the linear resistance of multi-strand cables and cords. This paper demonstrates that the main issue stems from inter-wires contact resistances. A new contacting method has been developed that allows mastery of this metrology task. 

Issue

Most of the equipment available on the market are for 25 pairs. However, measuring Alien Crosstalk requests connecting 28 pairs! The industry had to go around the problem by implementing different emergency tricks like multi-loading or merging results through Excel spreadsheet. All of them were subject to errors and very greedy of time and resources both in personnel and equipment. A full characterisation was requesting more than ten hours to complete.

AESA solution

It was decide to conceive a new test system dedicated to this Alien Crosstalk characterisation. Two different technologies were implemented, one with Radiall coaxial relays, the other with solid state switching. The Vega 1028 respectively 7528 allow now performing the full characterisation of a seven four pairs cables bundle in less than twenty minutes, cables preparation included. The effectiveness is overwhelming.

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