RE: board scanning on the cheap (sort of)
Hi Group, Didn't find much time lastly to contribute, but this topic always triggers something inside Do not forget that using such a system only the near field is found, in the orientation the probe determines. In general this has not much to do with the actual 3 or 10 meter emission. By performing relative measurements however, one gets a decent impression in terms of reducing or increasing values relative to a previous IDENTICAL measurement. The probe orientation as well as the distance MUST be well reproduced and the test should be repeated with several orientations of the probe. As an electric field probe (ideally) does not detect magnetic field and vice versa and both contribute to the total emitted radiation, a test in several directions and several operating modes should be conducted with both type of probes. One should also consider probing a PCB from 6 sides, as emission does not have to be maximal in the orthogonal direction of the top side of your PCB. If you're still enthiousiastic about such a project, consider buying a standard bi-conical antenna and create a 3m site on your parking using chicken mesh wire on the floor. I am sure you will get faster and more consistent results then using an XY table and close field probes. EMC is all about measurements in the far field of a source, both in terms of wavelength ( lambda/3 ) and geometrically relative to the EUT. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of brent.dew...@us.datex-ohmeda.com Sent: Wednesday, August 08, 2001 10:03 PM To: emc-p...@majordomo.ieee.org Subject: board scanning on the cheap (sort of) With all this talk about visualization, I thought I'd toss in my bit. Here at Datex-Ohmeda we have a small NC mill sometimes used by the RD group to make small prototype parts, but it often sits idle. Since I have a spectrum analyzer and a variety of small dimension H and E field probes I've built, I thought it would be interesting to build the equivalent of an EMScan. The control program is being written in LabVIEW and is coming along pretty well. One nice thing about the mill is that I can program the scan height for any rectangle I define, so tall components can be hopped over. When it's all done, I should be able to play a frequency swept movie of the board on an intensity graph. The cheaper way to do this would be to find an older X-Y plotter and skip the height variation. If I ever get the beast done, it will be open source to LabVIEW users. Best regards, Brent DeWitt Datex-Ohmeda Louisville, CO --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall, attachment: Gert Gremmen.vcf
Re: board scanning on the cheap (sort of)
Er..., I suppose your XY table have to be made of nylon or plastic, something that will not facilitate the common mode (surface) currents to flow. Tim Foo, (or just call me 'Tim') E-mail: f...@np.edu.sg ECE, School of Engineering, http://www.np.edu.sg/ece/ Tel: + 65 460 6143 Ngee Ann Polytechnic, Fax: + 65 467 1730 535 Clementi Road, Singapore 599489 brent.dewitt@us.datex-o hmeda.com To: emc-p...@majordomo.ieee.org Sent by: cc: (bcc: Wan Juang Foo/ece/staff/npnet) owner-emc-pstc@majordomSubject: board scanning on the cheap (sort of) o.ieee.org 08/09/01 04:02 AM Please respond to brent.dewitt With all this talk about visualization, I thought I'd toss in my bit. Here at Datex-Ohmeda we have a small NC mill sometimes used by the RD group to make small prototype parts, but it often sits idle. Since I have a spectrum analyzer and a variety of small dimension H and E field probes I've built, I thought it would be interesting to build the equivalent of an EMScan. The control program is being written in LabVIEW and is coming along pretty well. One nice thing about the mill is that I can program the scan height for any rectangle I define, so tall components can be hopped over. When it's all done, I should be able to play a frequency swept movie of the board on an intensity graph. The cheaper way to do this would be to find an older X-Y plotter and skip the height variation. If I ever get the beast done, it will be open source to LabVIEW users. Best regards, Brent DeWitt Datex-Ohmeda Louisville, CO --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall,
Re: board scanning on the cheap (sort of)
I think this was known as Kirlian photogrphy - spelling may be wrong. It can detect the electrostatic charge surrounding living tissue. Ralph Cameron - Original Message - From: geor...@lexmark.com To: emc-p...@ieee.org Sent: Thursday, August 09, 2001 4:00 PM Subject: board scanning on the cheap (sort of) Well, this discussion has reached the point where I must add something I read about some years ago. It goes something like this: For many years, Russia was known to conduct many experiments involving paranormal activity, probably to determine if there were any military value in such phenomena as psychic communications etc., if in fact they existed. I was surprised to see an article in a National Geographic years ago that told of one such experiment. It involved photography of the aura (presumably electromagnetic fields) that surround the human body. The peaks in this aura, or field were found to be consistent with the primary acupuncture points long before identified by the Chinese. A faith (hand-on) healing was photographed, revealing that the aura of the healer diminished during the process while the aura of the person being healed increased, i.e. a possible transfer of energy. The point of all this is if the Russians truly developed a means to photograph the low power EMF surrounding humans, it would seem that the same technique would also photograph the EMF surrounding PCBs etc. I have no comment on whether any of the above is true science, but I DID read it in the generally respected National Geographic, albeit not a scientific journal. George Alspaugh --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall,
RE: board scanning on the cheap (sort of)
I think your talking about Kirlian photography.Here is something verbatim from a web page that deals with it. http://www.synergy-co.com/kirlian.html#equipment Equipment Used to Produce Kirlian Images Kirlian photographs are created utilizing a metal plate, and a generator or oscillator to produce a high voltage field of variable pulse and frequency. There is no light used in this process. Through the action of high frequency fields, electrons are emitted from the body of an organism and this energy is dissipated into a photographic emulsion, as light would be. Different colors or shadings appear in a brilliant corona surrounding the object, depending upon the type of film used. I think the light source is Cherenkov radiation which I understand to be photons emitted when electrons move to lower energy orbits. Presumably the applied high frequency field energizes the atoms and moves the electrons to higher energy states? That might be an interesting way to find points for ESD testing? Perhaps it shows where the field tends to concentrate. The Kirlian pictures are always seem to have pointy fields. Well, that's at least 2 cents. -George -Original Message- From: geor...@lexmark.com [mailto:geor...@lexmark.com] Sent: Thursday, August 09, 2001 1:00 PM To: emc-p...@ieee.org Subject:board scanning on the cheap (sort of) Well, this discussion has reached the point where I must add something I read about some years ago. It goes something like this: For many years, Russia was known to conduct many experiments involving paranormal activity, probably to determine if there were any military value in such phenomena as psychic communications etc., if in fact they existed. I was surprised to see an article in a National Geographic years ago that told of one such experiment. It involved photography of the aura (presumably electromagnetic fields) that surround the human body. The peaks in this aura, or field were found to be consistent with the primary acupuncture points long before identified by the Chinese. A faith (hand-on) healing was photographed, revealing that the aura of the healer diminished during the process while the aura of the person being healed increased, i.e. a possible transfer of energy. The point of all this is if the Russians truly developed a means to photograph the low power EMF surrounding humans, it would seem that the same technique would also photograph the EMF surrounding PCBs etc. I have no comment on whether any of the above is true science, but I DID read it in the generally respected National Geographic, albeit not a scientific journal. George Alspaugh --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall,
board scanning on the cheap (sort of)
Well, this discussion has reached the point where I must add something I read about some years ago. It goes something like this: For many years, Russia was known to conduct many experiments involving paranormal activity, probably to determine if there were any military value in such phenomena as psychic communications etc., if in fact they existed. I was surprised to see an article in a National Geographic years ago that told of one such experiment. It involved photography of the aura (presumably electromagnetic fields) that surround the human body. The peaks in this aura, or field were found to be consistent with the primary acupuncture points long before identified by the Chinese. A faith (hand-on) healing was photographed, revealing that the aura of the healer diminished during the process while the aura of the person being healed increased, i.e. a possible transfer of energy. The point of all this is if the Russians truly developed a means to photograph the low power EMF surrounding humans, it would seem that the same technique would also photograph the EMF surrounding PCBs etc. I have no comment on whether any of the above is true science, but I DID read it in the generally respected National Geographic, albeit not a scientific journal. George Alspaugh --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall,
Re: board scanning on the cheap (sort of)
Can I point you to a commercial version already available. A company called 'Detectus AB' have a system like this - more details can be found at http://www.detectus.se/ I've used this system on several projects and it is very useful for visualising the emissions plot of a PCB / Chassis. Using this system we can view what happens on the top side of a PCB or around a chassis which was the limitation of the EMScan system. You can also use any type of probe for the measurements. The only downside to this system is that it can take a couple of hours for a scan of a pcb if using a small probe and cell size. EMScan has speed as it's main feature. Usual disclaimer - I have no links to either company and all views expressed are personal etc. etc. etc Ivor Eathorne 3Com Europe Ltd. UK. brent.dew...@us.datex-ohmeda.com on 08/08/2001 21:02:46 Please respond to brent.dew...@us.datex-ohmeda.com Sent by: brent.dew...@us.datex-ohmeda.com To: emc-p...@majordomo.ieee.org cc:(Ivor Eathorne/GB/3Com) Subject: board scanning on the cheap (sort of) With all this talk about visualization, I thought I'd toss in my bit. Here at Datex-Ohmeda we have a small NC mill sometimes used by the RD group to make small prototype parts, but it often sits idle. Since I have a spectrum analyzer and a variety of small dimension H and E field probes I've built, I thought it would be interesting to build the equivalent of an EMScan. The control program is being written in LabVIEW and is coming along pretty well. One nice thing about the mill is that I can program the scan height for any rectangle I define, so tall components can be hopped over. When it's all done, I should be able to play a frequency swept movie of the board on an intensity graph. The cheaper way to do this would be to find an older X-Y plotter and skip the height variation. If I ever get the beast done, it will be open source to LabVIEW users. Best regards, Brent DeWitt Datex-Ohmeda Louisville, CO --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall,
RE: board scanning on the cheap (sort of)
Brent, You'd find a paper titled Constructing the Lagrangian of VLSI Devices from Near Field Measurements of the Electric and Magnetic Fields on page 129 of the IEEE 2000 Symposium record volume one very interesting. It lists some results using just such a measuring device. A description I believe of the contraption itself can be found in the IEEE 1999 EMC Symposium record titled Measuring the Electric and Magnetic Near fields in VLSI Devices. Dan -Original Message- From: brent.dew...@us.datex-ohmeda.com [mailto:brent.dew...@us.datex-ohmeda.com] Sent: Wednesday, August 08, 2001 4:03 PM To: emc-p...@majordomo.ieee.org Subject: board scanning on the cheap (sort of) With all this talk about visualization, I thought I'd toss in my bit. Here at Datex-Ohmeda we have a small NC mill sometimes used by the RD group to make small prototype parts, but it often sits idle. Since I have a spectrum analyzer and a variety of small dimension H and E field probes I've built, I thought it would be interesting to build the equivalent of an EMScan. The control program is being written in LabVIEW and is coming along pretty well. One nice thing about the mill is that I can program the scan height for any rectangle I define, so tall components can be hopped over. When it's all done, I should be able to play a frequency swept movie of the board on an intensity graph. The cheaper way to do this would be to find an older X-Y plotter and skip the height variation. If I ever get the beast done, it will be open source to LabVIEW users. Best regards, Brent DeWitt Datex-Ohmeda Louisville, CO --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall,
RE: board scanning on the cheap (sort of)
-Original Message- From: brent.dew...@us.datex-ohmeda.com [mailto:brent.dew...@us.datex-ohmeda.com] Sent: Wednesday, August 08, 2001 1:03 PM To: emc-p...@majordomo.ieee.org Subject: board scanning on the cheap (sort of) With all this talk about visualization, I thought I'd toss in my bit. Here at Datex-Ohmeda we have a small NC mill sometimes used by the RD group to make small prototype parts, but it often sits idle. Since I have a spectrum analyzer and a variety of small dimension H and E field probes I've built, I thought it would be interesting to build the equivalent of an EMScan. The control program is being written in LabVIEW and is coming along pretty well. One nice thing about the mill is that I can program the scan height for any rectangle I define, so tall components can be hopped over. When it's all done, I should be able to play a frequency swept movie of the board on an intensity graph. The cheaper way to do this would be to find an older X-Y plotter and skip the height variation. If I ever get the beast done, it will be open source to LabVIEW users. Best regards, Brent DeWitt Datex-Ohmeda Louisville, CO Brent: That sounds like a good project. But what about the conductive / reflective effect of that big spindle? Maybe you should mount any probe on the end of a long, stiff non-conductive rod. Assuming that you can crank the table down pretty far, you might be able to chuck an 18 rod in the spindle. Regards, Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall,
board scanning on the cheap (sort of)
With all this talk about visualization, I thought I'd toss in my bit. Here at Datex-Ohmeda we have a small NC mill sometimes used by the RD group to make small prototype parts, but it often sits idle. Since I have a spectrum analyzer and a variety of small dimension H and E field probes I've built, I thought it would be interesting to build the equivalent of an EMScan. The control program is being written in LabVIEW and is coming along pretty well. One nice thing about the mill is that I can program the scan height for any rectangle I define, so tall components can be hopped over. When it's all done, I should be able to play a frequency swept movie of the board on an intensity graph. The cheaper way to do this would be to find an older X-Y plotter and skip the height variation. If I ever get the beast done, it will be open source to LabVIEW users. Best regards, Brent DeWitt Datex-Ohmeda Louisville, CO --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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.rcic.com/ click on Virtual Conference Hall,
