>-----Original Message----- >From: Donnelly, Thomas [mailto:tdonne...@act-sys.com] >Sent: Thursday, March 04, 2004 5:20 AM >To: EMC-PST (E-mail) >Subject: HIRF Testing > > > >Group, > >I am looking for a HIRF Test facility to do a test to N8110.71 Table 2 >levels which go as high as 3000V/m. Does anyone know of a lab with the >capability? > >I know TUV America has this capability but they don't seem to want to >respond to my requests for quote. I am very displeased with >their responses. >I requested a quote in early December. Never heard from them. >I requested >they contact me twice on their web page to get other quotes. >No response to >these queries. Has anyone else has similar experience with them? > >Thanks, > >Tom Donnelly >EMC Engineer >Smiths Aerospace >973-428-9898 x445 >tdonne...@act-sys.com
Tom: I'm not familiar with N8110, but allow me to say a few things. 3,000 V/m is a rather high field strength, and is not easily achievable. If the requirement is 3,000 V/m, swept over a frequency range, it will be difficult to find a lab that can really do that. Some labs will have odd items, perhaps an X-band radar set and a 4-foot diameter parabolic antenna. With that, they might easily achieve 25,000 V/m, but only peak, and only over the mechanical tuning limits of the radar's magnetron (like possibly 8.6 to 9.5 GHz). If you want more frequency coverage, or some other than the default modulation, you are out of luck. OTOH, if you just need a generic pulse that hits 3,000 V/m peak, then a number of labs can do this (although the bigger your test specimen, the fewer the labs). For instance, MIL-STD-461E defines a Method RS105, that calls for a 50 kV/m pulse. Plus, they show a sheet-metal antenna, easily within the building skills of any air-conditioning contractor. Unfortunately, the details about the pulse generator that drives this antenna are quite absent. <g> Some manufacturers, such as Maxwell Labs, made somewhat suitable, incredibly expensive pulse generators. Try looking for a lab associated with a large aerospace company. You might also try: http://www.lightningtech.com http://www.dynamiclabs.com http://www.baesystems.com in Lakewood NJ. R&B Industries used to have some kind of deal with the Navy viz the Pax River EMP facility. http://www.nawcad.navy.mil The USAF had a fantastic HIRF / EMP facility at Kirtland AFB, but I think they gave that to the Army guys at White Sands Missile Range. http://wstc.wsmr.army.mil/ Both the British & the French military have very good HIRF capabilities. I seem to recall Airbus Industries having a big facility in the south of France (Toulouse?). Getting back to the actual testing, there's two ways to do it. The best way is the straight forward, brute force approach: Illuminate the whole test specimen in a 3,000 V/m field, and see if it still works. This is easy to understand, but requires major lab facilities. (Think the most expensive test you ever paid for.) An alternate method is to determine "upset" values of current or voltage within your device. Let's assume you have a microprocessor reset line that will trip at 3.57 volts. Normally, there's only a few millivolts on that line. All you have to do is attach a probe to that line, and somehow monitor the voltage while an external RF field is applied to the device. If you can only generate a field of say, 300 V/m, then you verify that the internal reset line voltage never exceeds 0.357 volts during the moment of the external field application. The advantage is that you can test with much smaller fields. The problems here are that the scaling isn't necessarily linear, that you may contaminate the test with the presence of the monitor equipment, and that you may not be monitoring ALL of the critical circuit locations. A number of labs can put a couple of thousand volt pulse onto a stripline antenna, so this scaling approach is popular. It lets you get the test done, trading on increased complexity & time. Regards, Ed Ed Price ed.pr...@cubic.com WB6WSN NARTE Certified EMC Engineer & Technician Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Is Our Specialty This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ieee-pses.org/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
