1. For a long time it was stated in CISPR22/EN55022 that some regulatory agencies think that the clamp method is a good substitute for a OATS measurement. But this method never was accepted for CISPR22/EN55022 and can not be found in any other standard but CISPR14/EN55014. Why? 2. The clamp measures the HF power available on the wires going out of the equipment. But is that all? Why do we have to put so much attention on the enclosure seams of personal computers? Would you also put a clamp on the enclosure seam? 3. Putting all wires together into one clamp is certainly not a good idea. The HF-currents can add up, but as well can also cancel each other. 4.Look at a dipol antenna: In the middle a Balun (Power Source) Each side one rod coming out. Look at a personal computer: In the middle the computer, on each side a wire acting as antenna coming out. Do you think a absorber clamp can remodel that scenario?
Regards Rene Charton ---------- | ±H¥óªÌ: POWELL, DOUG <doug.pow...@aei.com> | ¦¬¥óªÌ: EMC-PSTC (E-mail) <emc-p...@ieee.org>; 'Treg (E-Mail)' <t...@world.std.com> | ¥D¦®: Pre-Compliance testing for radiated emissions using a current probe | ¤é´Á: 1999¦~2¤ë12¤é AM 03:28 | | Hello Group, | | Some time ago (1996) in an email thread on absorbing clamps, Michael A. | Royer stated that CISPR 14 defines a method for using current clamps instead | of open area test sites. There was another thread for an on-site radiated | emissions test when in noisy environments that mentioned using clamp-on | probes. | | Additionally I recall and article in one of the trade magazines (Compliance | Engineering, ITEM, etc.) that described a method where a person could bundle | all of the service connections for a product into an RF current clamp-on | probe. The article also had information on converting the data on a | spectrum analyzer into equivalent open area test site numbers. | | I would like to perform a test like this but have been unable to find a | clamp-on probe that has at least a 100mm inner diameter and a frequency | range of 30 MHz to 1000 MHz, possibly this is limited by physics. | | Is there anyone out there who is able to point me to articles or websites | on: | | 1) RF current probe manufacturers. | 2) The article and/or mathematical algorithm on measuring radiated | emissions with current probe. | 3) Application information. | | Thank you for any help you can provide. | | ================================== | Doug Powell, Compliance Engineer | Advanced Energy Industries, Inc. | Fort Collins, Colorado USA | | doug.pow...@aei.com | www.advanced-energy.com | ================================== --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
