Post by thread:[OT] Question - Berylium in Microwave oven magnetr

Does anyone know if Beryllium (or crushed PICs :-)) is ever used in the ceramic insulators in microwave oven magnetrons? They warn against high voltage and microwave radiation and don;'t mention beryllium so one would HOPE that they haven't resorted to such materials. But .... Not a material I would want to encounter accidentally. TIA Russell McMahon _____________________________ >From other worlds - http://www.easttimor.com http://www.sudan.com What can one man* do? Help the hungry at no cost to yourself! at http://www.thehungersite.com/ (* - or woman, child or internet enabled intelligent entity :-))

I think not because berillium ceramics is toxic -----Original Message----- From: Russell McMahon [spam_OUTapptechTakeThisOuTCLEAR.NET.NZ] Sent: Tuesday, March 14, 2000 5:18 AM To: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU Subject: [OT] Question - Berylium in Microwave oven magnetrons? Does anyone know if Beryllium (or crushed PICs :-)) is ever used in the ceramic insulators in microwave oven magnetrons? They warn against high voltage and microwave radiation and don;'t mention beryllium so one would HOPE that they haven't resorted to such materials. But .... Not a material I would want to encounter accidentally. TIA Russell McMahon _____________________________ >From other worlds - http://www.easttimor.com http://www.sudan.com What can one man* do? Help the hungry at no cost to yourself! at http://www.thehungersite.com/ (* - or woman, child or internet enabled intelligent entity :-))

Items that contain BeO that I have seen have a note to this effect on the external label. I cannot think of a reason why any item in a microwave oven would contain BeO. There is only two uses I am aware of for it. 1. Heat transfer capability in insulation washers. It has a lower thermal resistance per unit thickness than Aluminium Oxide. It used to be used in RF transistors for this reason (the early VHF high power types with the white disc washers). 2. It was used in early fluorescent tubes as one of the powders to coat the inside of the tube. Not used for many years because of its toxicity and the ease of breakage for these tubes.

It's also used extensively in the model boat propellers I use to provide light weight with strength, as part of a BeCu alloy. So if someday I'm not here, you might guess why. Andy Alan Pearce <A.B.PearceKILLspamRL.AC.UK> on 03/14/2000 07:00:07 AM Please respond to pic microcontroller discussion list <.....PICLISTKILLspam.....MITVMA.MIT.EDU> To: EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: Re: [OT] Question - Berylium in Microwave oven magnetrons? Items that contain BeO that I have seen have a note to this effect on the external label. I cannot think of a reason why any item in a microwave oven would contain BeO. There is only two uses I am aware of for it. 1. Heat transfer capability in insulation washers. It has a lower thermal resistance per unit thickness than Aluminium Oxide. It used to be used in RF transistors for this reason (the early VHF high power types with the white disc washers). 2. It was used in early fluorescent tubes as one of the powders to coat the inside of the tube. Not used for many years because of its toxicity and the ease of breakage for these tubes.

>Items that contain BeO that I have seen have a note to this effect on the >external label. I cannot think of a reason why any item in a microwave oven >would contain BeO. They appear to use a ceramic insulator between the Anode and the body. The Anode is going to get rather hot given the power levels involved and they will be aiming at best heat transfer here. Uh Oh !!!!!!!!!! The url that Jim Hratman provided - http://www.nsc.org/ehc/ew/chems/berylliu.htm says "Beryllium oxide is used to make specialty electrical and high-technology ceramics, electronic heat sinks, electrical insulators, MICROWAVE OVEN COMPONENTS" , gyroscopes, military vehicle armor, rocket nozzles, and laser structural components. Beryllium alloys are used in electrical connectors and relays, springs, precision instruments, aircraft engine parts, nonsparking tools, submarine cable housings and pivots, wheels, and pinions. RM

Russell, What did you do? Did you crack one of these and are now worried about the consquences? Or, is this just something you want to know for the future? Sean At 12:19 PM 3/15/00 +1300, you wrote: {Quote hidden}>>Items that contain BeO that I have seen have a note to this effect on the >>external label. I cannot think of a reason why any item in a microwave oven >>would contain BeO. > > >They appear to use a ceramic insulator between the Anode and the body. The >Anode is going to get rather hot given the power levels involved and they >will be aiming at best heat transfer here. > > >Uh Oh !!!!!!!!!! >The url that Jim Hratman provided - > http://www.nsc.org/ehc/ew/chems/berylliu.htm >says >"Beryllium oxide is used to make specialty electrical and high-technology >ceramics, electronic heat sinks, electrical insulators, >MICROWAVE OVEN COMPONENTS" , >gyroscopes, military vehicle armor, rocket nozzles, and laser structural >components. Beryllium alloys are used in electrical connectors and relays, >springs, precision instruments, aircraft engine parts, nonsparking tools, >submarine cable housings and pivots, wheels, and pinions. > >RM > | | Sean Breheny | Amateur Radio Callsign: KA3YXM | Electrical Engineering Student \--------------=---------------- Save lives, please look at http://www.all.org Personal page: http://www.people.cornell.edu/pages/shb7 shb7spam_OUTcornell.edu ICQ #: 3329174

I know that a lot of magnetrons for marine radars have Be and are not always markes as containing it directly on the magnetron. There is usually a marking on the box. ----- Original Message ----- From: Pavel Kristek <@spam@KristekKILLspamINTERBELL.CZ> To: <KILLspamPICLISTKILLspamMITVMA.MIT.EDU> Sent: Tuesday, March 14, 2000 6:48 AM Subject: Re: [OT] Question - Berylium in Microwave oven magnetrons? > I think not because berillium ceramics is toxic > > {Original Message removed}

So, Russell, were you melting metal in the microwave and it blew? if you're worried about contamination, the dust is the bad stuff. DO NOT BREATHE IT. otherwise, its not so bad. Use a solution of water and detergent, simple green is nice but i dont know if they have it in NZ--this has a wetting agent that helps wet the dust so it doesnt go into the air. Drop in two drops of water-color pigment, or food color or ink.... Mist-spray this solution into the cavity of the microwave, the workbench, or anything you have touched, including the light switches etc, to stabilize the dust, but dont get it all runny. Now get some disposable gloves, dry paper towels, and clean up the mess and put it in a double plastic trash bag. the food coloring is there to tell you when its clean, and where it is. although one exposure probably wont kill you, chronic exposure is the problem. alice so did it melt? > here's some info - http://www.nsc.org/ehc/ew/chems/berylliu.htm