A lump of coal will heat up in a microwave oven. No water needed. It is the bulk resistivity of an object which allows circulating currents to generate heat, and while water can help (when we wet something, its chemical bonds are a source of electrons) it is not the only thing that is heated in a microwave oven.
The cones from our chambers don't have water in them (better not, anyway) and they'll not only heat up in the microwave, but burn with a nasty, nasty smell. The carbon conducts, the foam that holds it burns. Not to denigrate water's action; I remember reading that a serviceable Radar Absorbing Material may be made by wetting foam urethane. But the frequency of microwave ovens wasn't chosen for resonance with water. (PURE, distilled water is an insulator. I wonder if 2450 is close enough to even warm it up?) Cortland ====================== Original Message Follows ==================== >> Date: 23-Apr-01 02:07:07 MsgID: 1078-34037 ToID: 72146,373 From: David Instone >INTERNET:david_inst...@uk.xyratex.com Subj: Re: 2. 4 GHz cordless telephone, question of general interest Chrg: $0.00 Imp: Norm Sens: Std Receipt: No Parts: 1 List-Post: emc-pstc@listserv.ieee.org Date: Mon, 23 Apr 2001 09:05:38 +0100 From: david_inst...@uk.xyratex.com (David Instone) Subject: Re: 2. 4 GHz cordless telephone, question of general interest Reply-To: david_inst...@uk.xyratex.com (David Instone) Ken Javor wrote: > > Just goes to show you can find anything on the net. I have measured leakage > from microwave ovens and every one was at 2450 MHz. And that IS a resonant > frequency for water and water alone. That's why you can put waterless items > in and they won't heat up, Hm, now I wonder how the the totally dry and empty pottery plate I put in the microwave to heat (before I put my non microwave cooked food on it) gets too hot to hold after just 60 seconds at 650W. > and also why you should never run a microwave > oven without a water load: with no load you get high vswr and the magnetron > can be damaged by reflected energy. -- Regards Dave Instone. Compliance Engineer Storage Systems Development, MP24/22 Xyratex, Langstone Rd., Havant, Hampshire, P09 1SA, UK. Tel: +44 (0)23-92-496862 (direct line) Fax: +44 (0)23-92-496014 http://www.xyratex.com Tel: +44 (0)23-92-496000 ------------------------------------------- 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 Heald davehe...@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," **Primary Recipient: Ken Javor INTERNET:ken.ja...@emccompliance.com ====================== End of Original Message ===================== ------------------------------------------- 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 Heald davehe...@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,"
