Microwave oven - A WTF experience

[Gilded]

First of all, sorry for my absence lately. With all this spare time I have at the moment (no school, no work) I think I've been directing too much of it to gaming rather than something constructive... say, science. Luckily, there was something that sparked my interest again.

 

This has been bothering me for quite a while actually. While I'm not the kind of person that warms everything he can in the microwave, I sometimes warm sausages or meatballs or such. Well, today I had some meatballs in the microwave and after a few seconds of warming a sudden spark occurred between two meatballs that were right next to each other. This was clearly an electric arc, and the distinct smell of electric burning was noticed afterwards. This has happened earlier with sausages, and sometimes with vegetables. Basically it's two pieces of moist organic matter in the microwave, and for some reason the contact point between them burns up (pretty vigorously I might say).

 

So, why does this happen? Eddy currents? During my high school physics I went from quite basic electromagnetism to theoretical physics/relativity so one might say this isn't my sharpest area. Anyhow it's most annoying, as electrically burnt food often tastes rather bad.

[Genecks]

Not sure. I would suggest getting a new microwave.

[YT2095]

it`s caused by standing waves.

the RF induces a current in the conductor (a sausage) MWs work at roughly 2Kv and at several GHz.

so the wavelength will be in cms, so you may get a 1 or 2 complete wave cycles per sausage, if there are 2 sausages and they`re not Co-Phased properly, you can get the Peak of a wave in one end and the trough of a wave in another, thus creating a large PD and Zap, it`ll arc over if it`s close enough.

[imp]

it`s caused by standing waves.

the RF induces a current in the conductor (a sausage) MWs work at roughly 2Kv and at several GHz.

so the wavelength will be in cms, so you may get a 1 or 2 complete wave cycles per sausage, if there are 2 sausages and they`re not Co-Phased properly, you can get the Peak of a wave in one end and the trough of a wave in another, thus creating a large PD and Zap, it`ll arc over if it`s close enough.

 

In all the time my wife has sold microwave ovens, and taught cooking classes, I don't believe I've ever heard of meat products behaving as described. Perhaps the sausages had free-metallic ions in them?

 

I would get a new microwave AND different sausages! Imp.

[YT2095]

I can assure you that Sausages and Pickles and anything with a high enough salt water (sodium ions in this case) is Plenty conductive enough

[imp]

I can assure you that Sausages and Pickles and anything with a high enough salt water (sodium ions in this case) is Plenty conductive enough

 

Ah, yes, ionized liquid content of foodstuffs, I forgot! And after the fact of the post, my wife assured me she did on a few occasions, witness arcing unexpectedly.

 

For general interest, the Shar Micro-Convection oven have a metallic turntable, instead of glass/quartz, and apparently the loading effect on the magnetron is calculated to avoid arcing. My store-wrapped Arby's sandwiches once caught fire; the wrappings contained aluminized paper.

 

Imp.