I am fortunate to have our company's shipping department located immediately next to my lab. I often use empty cardboard boxes to build non-conducting platforms. It's surprising how much weight a taped box can support. There are several densities of urethane foam, but there is also a white foam made from polyethylene (or maybe polystyrene). This stuff is so strong that you can't hardly make a dent in it with your thumb. Finally, there is the foam which is used for foam-in-place packing. This stuff is poured into a box like a bubble-bath, and then cures to a hard foam. Fill an empty cardboard box with this foam, and you can get a very tough support structure. Ed Price <mailto:[email protected]> [email protected] 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
_____ From: [email protected] [mailto:[email protected]] On Behalf Of Kunde, Brian Sent: Thursday, January 24, 2008 5:23 AM To: Grace Lin; Bill Stumpf; [email protected] Cc: [email protected] Subject: RE: Table for Measuring Emission for Desktop Equipment We have products that are benchtop models that weigh over 400 lbs. We have to sit the product on the test table with a boom lift and roll it into the chamber. How can we do this with styrofoam? The Other Brian _____ From: [email protected] [mailto:[email protected]] On Behalf Of Grace Lin Sent: Thursday, January 24, 2008 7:44 AM To: Bill Stumpf; [email protected] Cc: [email protected] Subject: Re: Table for Measuring Emission for Desktop Equipment Ari and Bill, Thank you so much for sharing your knowledge and experience, especially for the photo sent by Ari. Is there any other material good for high frequency measurement? Some of our products weight 75 lb. For styrofoam block, I probably need to build a solid 1.5mx1mx0.8m styrofoam block. This would be interesting. Best regards, Grace On 1/23/08, Bill Stumpf <[email protected]> wrote: Agreed! Commonly known as "Blue board" or "DOW board", this type of closed-cell insulation works best for high-frequency testing. You can usually find it at lumber yards. Be careful of glues as they often have a dielectric characteristic themselves. We end up replacing our top layer of foam often since it does get chewed up... Bill Stumpf _____ From: [email protected] [mailto: [email protected] <mailto:[email protected]> ] On Behalf Of [email protected] Sent: Wednesday, January 23, 2008 9:22 AM To: [email protected] Subject: RE: Table for Measuring Emission for Desktop Equipment We have a great table that is made of styrofoam. The material is about 10 cm thick, originally intended for thermal insulation of buildings. Look from local hardware store. The sheets can be glued together to get a stronger table. Only drawback is the soft surface. Have a thin polycarbonate, etc. sheet on it or just be careful. Good luck! Ari Honkala _____ From: [email protected] [mailto: [email protected] <mailto:[email protected]> ] On Behalf Of ext Grace Lin Sent: 23. tammikuuta 2008 14:39 To: [email protected] <mailto:[email protected]> Subject: Table for Measuring Emission for Desktop Equipment Dear Members, Could someone recommend the sources for a 1mx1.5mx0.8m table (or materials to make a table) that is good for high frequency measurement? According to the latest 61000-4-3, a wooden table is not good for taking measurement above 1GHz. A friend mentioned styrofoam block. He doesn't know where to find it. Thank you and look forward to hearing from you. Best regards, Grace - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
