Microwave oven leakage question

[PowerEngineer]

I agree that it seems unwise to use any microwave oven that has been damaged.

My own experience is that my large high-power Panasonic microwave does interfere a bit with my home wifi(G). Not really noticeable for regular web browsing, but my son immediately sees it when playing on-line Starcraft. (Why he tries to play it on the kitchen table over wireless rather than somewhere he can use ethernet I'll never know...) I replaced the first one after two years (electronics failure) with another of the exact same model (it fits the built-in hole in the wall), and the wifi interference was the same.

This is it: http://www.amazon.com/Panasonic-NN-H...ref=pd_sbs_k_3

I see that one of the reviewers also mentions wifi interference.

So it's fair to say that some microwave ovens can interfere with wifi without being damaged. Certainly not a desirable feature!

 

[Throckmorton]

The interference means it's leaking more microwaves than it should. End of story. Take it to the nearest recycling center/dump and get a new microwave.

 

[xalos]

The microwave is fine to use. The glass itself doesn't do anything in regards to stopping RF or Microwave leakage. Its also normal for microwave ovens to knock out other 2.4 ghz wireless devices broken or not. Feel free to replace the oven if you have the money, but don't scrap the microwave before pulling out the transformer and the capacitors. Lots of entertainment and educational value there.

 

[Modelworks]

The microwave is fine to use. The glass itself doesn't do anything in regards to stopping RF or Microwave leakage. Its also normal for microwave ovens to knock out other 2.4 ghz wireless devices broken or not.

It is not fine to use or normal. A microwave should not cause wifi to drop, it would fail certification if it did so and breaks several FDA rules if it does. The glass doesn't stop leakage, it is the metal mesh inside the glass that does that.

The rules for microwaves are clear

c)Requirements --(1)Power density limit. The equivalent plane-wave power density existing in the proximity of the external oven surface shall not exceed 1 milliwatt per square centimeter at any point 5 centimeters or more from the external surface of the oven, measured prior to acquisition by a purchaser, and, thereafter, 5 milliwatts per square centimeter at any such point.

If your router is anywhere but directly on top of or next to the microwave and it drops the connection that microwave is leaking outside the limits.

 

[xalos]

It is not fine to use or normal. A microwave should not cause wifi to drop, it would fail certification if it did so and breaks several FDA rules if it does. The glass doesn't stop leakage, it is the metal mesh inside the glass that does that.

The rules for microwaves are clear


If your router is anywhere but directly on top of or next to the microwave and it drops the connection that microwave is leaking outside the limits.

I really don't think that rule is followed...lol Just because something is a law doesn't mean it is enforced. We're supposed to honk our horns when we pass people in our cars where we live, but we never do (unless we want to get the middle finger) and we never get cited.

Each microwave can operate at a different frequency in the 2.4 ghz range and affect different channels. The OP can probably change the channel and fix the problem with his router (Not sure why everyone focused on the microwave in the thread). Most people don't realize the effect microwaves can have on wifi because routers are smart enough to simply change the channel automatically. But, the OP could have oversaturation on the 2.4 ghz spectrum that makes the problem more noticeable.

If the first say 6 channels are being used up by randomness (we will ignore the fact that some of those channels shouldnt be used regardless) the microwave can clog up channels 6-9 and you have dropped or degraded wireless.

I suppose the OP could fix the oven too. Just buy some aluminum tape and cover the outside of the window on the door.

 

[Modelworks]

I really don't think that rule is followed...lol Just because something is a law doesn't mean it is enforced. We're supposed to honk our horns when we pass people in our cars where we live, but we never do (unless we want to get the middle finger) and we never get cited.

The rule is followed but the problem is no further testing is done after the units are sold. It is okay if a microwave lowers wifi quality while it is operating, it doesn't take much power to do that. What is not okay is if it completely breaks the wifi connection because that tells you that the output from the microwave is greater than the output from the wifi radio, which is usually at least 20mw.

The problem with the leakage is that without some easy way to measure it there is no way to know how bad it is, but overriding a 20mw signal in another room is a good indicator. I have seen microwave emit 135mw at 4 feet from the unit because the oven was dropped during shipping and it dislodged the mesh screen by just a few millimeter.

 

[xalos]

The rule is followed but the problem is no further testing is done after the units are sold. It is okay if a microwave lowers wifi quality while it is operating, it doesn't take much power to do that. What is not okay is if it completely breaks the wifi connection because that tells you that the output from the microwave is greater than the output from the wifi radio, which is usually at least 20mw.

The problem with the leakage is that without some easy way to measure it there is no way to know how bad it is, but overriding a 20mw signal in another room is a good indicator. I have seen microwave emit 135mw at 4 feet from the unit because the oven was dropped during shipping and it dislodged the mesh screen by just a few millimeter.

/shrug, if you're correct and I am wrong ... the world is filled with dangerous microwave ovens that need to be replaced because they are putting out dangerous leakage levels because they're severely degrading or knocking out wifi connections.

If I'm correct, the microwave is probably fine and he just has a weak signal on the client or some issue with noisy channels, oversaturation or something. Either way, aluminum tape around the exterior of questionable spots would fix any leakage problems.

 

[jjsbasmt]

I came across an interesting test (experiment) concerning emissions from a microwave oven. Put your cell phone in the microwave (don't turn the microwave), close the door and call your cell phone. If it rings, signals are getting in, and it would be assumed that microwaves would leak out as well. I tried this with my HTC Incredible, and the phone did not ring in my Sharp Carousel oven. DISCLAIMER; This is by no means inferred to be a legitimate method to test a microwave oven.

 

[wirednuts]

i think your cell phone puts off slightly less powerful microwaves then your microwave oven does, so they would be hard to compare.

 

[j03h4gLund]

Just replace it?

I dont understand why someone who knowinling uses a broken microwave would continue to use it so they dont have to spend $50. Seems like a cheap price to pay to prevent being nuked in your own home.

It's like... I know my my front right tire is bald, but I think Im going to try to stretch every last millimeter of life outta it so I can save myself spending $100 to fix it.... and possibly die in the process.

Makes no sense.. replace it.

 

[bryanl]

Hi all
A couple of years ago I smashed the front glass out of our microwave. IIRC it was tempered tinted glass. The perforated metal sheet behind it was slightly dented, but otherwise undamaged, and none of the 1/8 (?) inch holes were compromised. I took it to a small appliance repair shop locally and they didn't seem to think it was a problem, and we could go on using it safely.

What microwave leakage detector did the repair shop use -- brand model number, and NIST certificate, and what leakage levels did it show? You want something in writing indicating all that information. The good leakage detectors cost at least hundreds of dollars and are tuned to the frequency generated by microwave ovens. The bad ones, which sell for $2-$100, aren't tuned very well, if at all, and often react to every frequency, even 60 Hz AC electric fields, or they don't indicate any emissions, even when placed inside a microwave oven.

 

[DrPizza]

Here's a question: is the limit on microwaves set to protect human health (seems they're way over-protective in that case)? Or, rather, is the leakage limit set to prevent interference with other electronics - the exact problem the OP is experiencing? If it's leaking 50 watts, I really don't think that's a big deal. I have a 100 watt lightbulb that is emitting energy with higher frequency photons - i.e. "more damaging". Thus, I think Gaatjes thoughts on heating are irrelevant, unless all the leakage occurred through one damaged hole in the mesh & you put your body very close to it.

 

[William Gaatjes]

Here's a question: is the limit on microwaves set to protect human health (seems they're way over-protective in that case)? Or, rather, is the leakage limit set to prevent interference with other electronics - the exact problem the OP is experiencing? If it's leaking 50 watts, I really don't think that's a big deal. I have a 100 watt lightbulb that is emitting energy with higher frequency photons - i.e. "more damaging". Thus, I think Gaatjes thoughts on heating are irrelevant, unless all the leakage occurred through one damaged hole in the mesh & you put your body very close to it.

The heating was a bit extreme of an extreme example i admit. But in the other thread it is mentioned that the retina is extremely sensitive to radiation. And that permanent damage would not be noticed until it is way too late. IIRC the retina could be damaged before you would notice it. How much radiation needs to leak out to do permanent damage to the retina ? I do not know. But i myself would not take that chance. :hmm:

 

[TecHNooB]

Here's a question: is the limit on microwaves set to protect human health (seems they're way over-protective in that case)? Or, rather, is the leakage limit set to prevent interference with other electronics - the exact problem the OP is experiencing? If it's leaking 50 watts, I really don't think that's a big deal. I have a 100 watt lightbulb that is emitting energy with higher frequency photons - i.e. "more damaging". Thus, I think Gaatjes thoughts on heating are irrelevant, unless all the leakage occurred through one damaged hole in the mesh & you put your body very close to it.

light bulb wattage and power in the electric field are two different things.

 

[Modelworks]

Here's a question: is the limit on microwaves set to protect human health (seems they're way over-protective in that case)? Or, rather, is the leakage limit set to prevent interference with other electronics - the exact problem the OP is experiencing? If it's leaking 50 watts, I really don't think that's a big deal. I have a 100 watt lightbulb that is emitting energy with higher frequency photons - i.e. "more damaging". Thus, I think Gaatjes thoughts on heating are irrelevant, unless all the leakage occurred through one damaged hole in the mesh & you put your body very close to it.

The limits on microwave ovens are governed by the FDA. The FCC doesn't get into it much because the 2.4Ghz spectrum is unlicensed. A microwave oven that leaks over the limit is breaking part 15 FCC rules that state you cannot cause harmful interference . The FDA is in control because of both the direct harm to human tissue and the harm to people wearing things like pace makers.

The problem with a damaged microwave is their is no indicator a home user can use to determine exactly how bad the leakage may be. If it is damaged like in the OP it could be leaking 1 watt or 1000 watts and their would be no way to tell until the damage is done.


Here is the FDA page on the rules.
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=1030&showFR=1


They really get serious on the interlocks for the door to prevent idiots from defeating the safeties.

(i) Microwave ovens shall have a minimum of two operative safety interlocks. At least one operative safety interlock on a fully assembled microwave oven shall not be operable by any part of the human body, or any object with a straight insertable length of 10 centimeters. Such interlock must also be concealed, unless its actuation is prevented when access to the interlock is possible. Any visible actuator or device to prevent actuation of this safety interlock must not be removable without disassembly of the oven or its door. A magnetically operated interlock is considered to be concealed, or its actuation is considered to be prevented, only if a test magnet held in place on the oven by gravity or its own attraction cannot operate the safety interlock. The test magnet shall be capable of lifting vertically at zero air gap at least 4.5 kilograms, and at 1 centimeter air gap at least 450 grams when the face of the magnet, which is toward the interlock when the magnet is in the test position, is pulling against one of the large faces of a mild steel armature having dimensions of 80 millimeters by 50 millimeters by 8 millimeters.
(ii) Failure of any single mechanical or electrical component of the microwave oven shall not cause all safety interlocks to be inoperative.

 

[xalos]

The limits on microwave ovens are governed by the FDA. The FCC doesn't get into it much because the 2.4Ghz spectrum is unlicensed. A microwave oven that leaks over the limit is breaking part 15 FCC rules that state you cannot cause harmful interference . The FDA is in control because of both the direct harm to human tissue and the harm to people wearing things like pace makers.

The problem with a damaged microwave is their is no indicator a home user can use to determine exactly how bad the leakage may be. If it is damaged like in the OP it could be leaking 1 watt or 1000 watts and their would be no way to tell until the damage is done.

If I come across a microwave that I can trash I'll run some experiments for everyone (including busting the front glass out) to show how microwave leakage works.

A regular person could easily check their microwave leakage with a candy bar or something (props to how microwaves were discovered). It wouldn't be quantitative but I probably wouldnt hang out around a running microwave that was melting candy outside of it..lol (Well, I might...I forget to close up faraday cages all the time)