microwave oven

[starnbar]

This house we bought has a built in micro oven been using it for about 4 years now but it gave me a scare today I was reheating some food and I placed my bread with the cold butter right under the oven and 20 seconds later I saw the butter was melted on the bread. I thought well maybe the fan exhausts straight down then when I looked the fan exhausts out of the top. I have no idea it has been like this and the seal around the oven is good no cracks or cuts/tears that thing is coming out today I don't know if I am gonna get another one either my grandkids use it when they come over they make popcorn and cook hot pockets and I am really worried that they have been exposed to something that may not show up for years. I am just sick over this and I found this problem by accident. I am gonna get one of those detectors for micro leakage but if it can melt butter over a foot away under the oven it has got to be bad.

[MaryB]

Gas oven? Pilot light?

[dangitgriff]

Does your cat sleep in that spot on cold nights?

[rancher1913]

I know years ago all microwaves used in public areas (think vending area) had to be checked and certified that they were safe once a year. I would go with the stove being warm and not the microwave being the problem. unless the microwave was in use, it could not give off radiation.

[gwpercle]

Check your door seals , hinges and latch . There aren't many places a microwave oven can leak microwaves from . Also inspect the interior surfaces for any gaps .
Might want to call in a small appliance tech. and have it serviced or replaced if it's leaking too much .

Microwaves are not deadly like radiation .
Gary

[Winger Ed.]

I remember in the days when micro waves ability to heat things was just being discovered.

The guy who invented the 'radar range' discovered the concept because a chocolate bar melted in his shirt pocket
when he was doing something else with the micro wave generator/machine.

I know they're better sealed, and they've been all figured out by the time we could buy one.
However; I just don't trust them completely.

When we use ours, we always walk away from it a little ways until it turns itself off.
Does it make a difference? I don't know, but I feel better doing it.

[bakerjw]

The housing is usually a pretty good Faraday cage to keep the waves internal. If there is nothing rusted then it is likely a different source.
But still something to be noted.

[MT Gianni]

How old is the house? I would assume the oven is the same age. They do not last forever.

[cwtebay]

Fairly simple to test. Cello tape some uncooked popcorn on various places around the microwave, as mentioned the faraday cage is generally pretty effective, but if there's a defect - the corn will pop.

Sent from my Pixel 3 XL using Tapatalk

[jsizemore]

Glass of water with a thermometer under the microwave should tell the story.

[MaryB]

Microwaves cannot turn a corner without a reflector of some sort. Door seal leakage would be straight out the door to cabinet space for example, it won't turn and go to the front of the machine. It needs a metal surface to reflect off of... directly under the only thing I could think of is the plate motor(if it has one) is defective or missing letting microwaves out that hole...

[oldred]

As has already been said microwaves are not deadly like ionizing radiation however even a fire emits a form of radiation as heat so the term "radiation" does not always equate to deadly, or even dangerous for that matter. It's my understanding the energy in the form of microwaves from an oven would only penetrate about 1/4" (quite likely even less) so unless you feel it as you might feel the heat from bright sunlight then it shouldn't cause any harm. I was told that standing directly in the harsh bright sunlight is more harmful than any leakage that might occur around micro-oven seals.

[brassrat]

You're in FLORIDA

[farmbif]

does anyone think there there would be some agency or entity that would let us the general public know if an appliance that generates untold riches to huge corporations were not safe. all regulating agencies have been muted in effort to keep the money flowing.
a research scientist at a major technical university in Australia did a huge study on what kinds of radio waves come out of cellular phones a dozen. years ago or so. What they found was that cell phone held to your ear is just about like putting your head in a microwave oven and turning it on high. only the cell phone radiation is actually much worst because it is pulsed radiation.
just saying that microwave ovens probably are not that good for us. but like everyone else they work. as I just pulled a plate of left over jambalaya out of the radar range for lunch.

[MT Gianni]

A friend was in an advanced level engineering class when the professor stated that the air at the fence surrounding three mile island 6 months after the incident had 1/8th the radiation of uptown Butte, MT. If potatoes were a new product they would be banned as most all exceed arsenic levels by a large amount of that approved by the FDA.
There are two opinions about these statements. We either live in a namby-pamby state where idiots are trying to run our lives for the benefit of their chronies or the gov't needs to take better care of us. Run your life according to which you believe.

[oldred]

And then there is Dihydrogen monoxide, never mind the fact that millions of people have died from this substance it is still with us! It can cause asphyxiation, death from hypothermia and thousands die from encountering it in it's solid state, you can even die from toxic effects if you consume too much yet the Government allows the populace to continue to be exposed to the stuff!

[MaryB]

does anyone think there there would be some agency or entity that would let us the general public know if an appliance that generates untold riches to huge corporations were not safe. all regulating agencies have been muted in effort to keep the money flowing.
a research scientist at a major technical university in Australia did a huge study on what kinds of radio waves come out of cellular phones a dozen. years ago or so. What they found was that cell phone held to your ear is just about like putting your head in a microwave oven and turning it on high. only the cell phone radiation is actually much worst because it is pulsed radiation.
just saying that microwave ovens probably are not that good for us. but like everyone else they work. as I just pulled a plate of left over jambalaya out of the radar range for lunch.

Sorry but that is NOT accurate. Both are around the same frequency but a microwave is 1,000 watts versus 1/2 watt for a cell phone. A cell signal is NOT pulsed, it is modulated and never exceeds 1/2 watt and is often a lot less because the phone and tower talk to each other and control the power level.

One of these an tell you what is transmitting in your house http://www.randl.com/shop/catalog/product_info.php?products_id=75243&osCsid=ue73unkl7us4i8ebf9c8vbqs84

I would add a small microwave antenna like the 850 to 6500mhz antenna on this page(order via the drop down at the top of the page) https://wa5vjb.com/products1.html

Lets you snoop and see how much leakage your microwave has, start far away and do not exceed the input max of the spectrum analyzer! Fun little unit to play with, I picked one up for power line noise hunting that interferes with my ham radio receivers.

[.45Cole]

Microwaves are generated by a cavity magnetron in your microwave. This radiation is relatively weak and will not "stick around" anymore than light from a lightbulb. The microwaves (misnomer as this describes a range of wavelengths) have been targeted for certain frequencies that excite water molecules. If you "leaked" radiation from the microwave you would absorb it on your skin or surroundings (just heat things up). During the beginning of cavity magnetron research many people went blind as the radiation was heating up their corneas for which there is no nerves to signal increased temperature. You're fine, probably not the microwaves but may be the cooling air exhaust (hot air) generated by cooling of the cavity magnetron. Also not dangerous.

[Mal Paso]

When we use ours, we always walk away from it a little ways until it turns itself off.
Does it make a difference? I don't know, but I feel better doing it.

Yes it does. The radiation follows the Inverse Square Law: Intensity=1/Distance Squared. A few feet make a big difference.

[oldred]

Actually even a few inches make a big difference!

[MaryB]

Microwaves operate at 2.4ghz and I would post an RF safety calculator but that is for antenna radiation... leakage from a microwave will be much smaller. I posted the wrong spectrum analyzer up above, that one is good to 900 mhz only, to low for microwave ovens. This one and a laptop and free software go to 4.4ghz so it covers microwave ovens https://www.ebay.com/itm/Simple-Spectrum-Analyser-D6-With-Trace-Generator-Tracking-Source-T-G-V2-032-New/323842358121?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

[dangitgriff]

Very cool, MaryB, but where’s the DC block and probe? Integrated in the data cable?
I have used a homemade probe made out of a 1.5” section of semi-rigid coax before. It was good for verifying mixer outputs in dynamic test conditions but you couldn’t rely on the amplitude readings.
https://uploads.tapatalk-cdn.com/20200914/31a3fa6401e843a9ec23691c8e1abb8d.jpg

[MaryB]

For testing microwave oven leakage I would grab one of those antennas I linked in my first spec analyzer posts, the 850 - 6500 MHz on this page has 6dbi gain so have to factor that into your measurements https://wa5vjb.com/products1.html being directional it lets you make sure the issue is the microwave and not something else...

I would kill to have a real Spec analyzer but not in my budget!!!! Most of my measurements are transmitter so I would be using a dummy load with a tap to take off a tiny amount of power. The little micro analyzer with a screen I picked up is going to be used for power line noise hunting. As a ham radio operator I get a lot of interference from the junk they call the power system out here. Going to pair a small 3 element 2 meter beam with it(I do moon bounce on 2 meters so I have VERY sensitive receive on that frequency) to go out and check suspected bad spots.

2.8" screen, 100khz to 960mhz fully self contained and only $50. Yes Chinese so nothing expensive http://www.randl.com/shop/catalog/product_info.php?products_id=75243&osCsid=ue73unkl7us4i8ebf9c8vbqs84

http://www.randl.com/shop/catalog/images/dataimages/nanovna/tinysa.jpg

[fcvan]

HAM radio operator working on ‘gunplexer’ antennas to transmit microwaves between the 2 antennas, melted the chocolate. Radio can be fun but can still cook yer innerds. Having RF in the shack is not a good thing.

[dangitgriff]

Thanks for your recommendation, Mary B...that looks like something I can use in my current program—I’m back in the field. I transferred out of my old test lab when the program I worked on reached end-of-contract...they closed the site. I was a radar test engineer for a L-band radar, the L-88(V)3 and its predecessor, the L-88A. Unique systems.
R/Griff

[MaryB]

HAM radio operator working on ‘gunplexer’ antennas to transmit microwaves between the 2 antennas, melted the chocolate. Radio can be fun but can still cook yer innerds. Having RF in the shack is not a good thing.

Gunplexer horn antennas had around 20db of gain if my memory serves me, so your effective radiated power was considerably higher than the 100 milliwatts they put out. Around 6 watts and if the chocolate sat awhile it might melt it...

Nobody plays with wide band anymore, narrow band transverters for 10ghz are under $1k with 3 watts output on transmit and 1.5db noise figure.

[MaryB]

Thanks for your recommendation, Mary B...that looks like something I can use in my current program—I’m back in the field. I transferred out of my old test lab when the program I worked on reached end-of-contract...they closed the site. I was a radar test engineer for a L-band radar, the L-88(V)3 and its predecessor, the L-88A. Unique systems.
R/Griff

Not a lab grade instrument, you CAN connect it to a computer for a larger screen and easier use, the 960mhz limit is the downside. Wish they made one that went to 20ghz since I am starting to play around on 10ghz with the goal of doing moon bounce communications with it. That is using the moon as a reflector and bouncing a signal off it to be received all around the world if the other station can see the moon!

[10x]

https://www.google.com/search?sxsrf=ALeKk01vPHBw3LqXXL94n8oa-5j3k_ms8w%3A1600428187049&ei=m5hkX4W_As28-gScn5OoCg&q=check+microwave+with+flourecent+tube&oq=check+microwave+with+flourecent+tube&gs_lcp=CgZwc3ktYWIQAzIKCCEQFhAKEB0QHjIKCCEQFhAKEB0 QHjIKCCEQFhAKEB0QHjoECAAQRzoECCMQJzoFCAAQsQM6CAgAE LEDEIMBOgoIABCxAxCDARBDOgQIABBDOgcIABCxAxBDOgkIABB DEEYQ_wE6AggAOgcIABAUEIcCOgQIABAKOgYIABAWEB46CAghE BYQHRAeOgcIIRAKEKABOgQIIRAVOgQIIRAKUNchWKGJAWCciwF oAHACeACAAfEBiAGGGZIBBjMwLjUuMZgBAKABAaoBB2d3cy13a XrIAQjAAQE&sclient=psy-ab&ved=0ahUKEwjF-M7My_LrAhVNnp4KHZzPBKUQ4dUDCA0&uact=5

Look for a reaction.
If your microwave leaks, the fluorescent tube will glow, or the neon bulb will become noticeably brighter. Electronic testers react in different ways, so check the manual. If the tester displays a measurement, anything about 5 mW/cm2 at a distance of 5 cm (2 inches) is cause for concern.

[redhawk0]

I know the back of my oven has a vent that heat/steam escapes from. If you set the bread/butter near that...it would account for the melt. I'd test it again...several times in fact...see if you can duplicate it. If you can't...(and likely won't) Don't worry about it....By the way....if you don't put your head on the cook top when using the microware...you'll be fine.

redhawk