Test Microwave for Radiation Leakage(ismymicrowaveleaking.isotropic.us) |
Test Microwave for Radiation Leakage(ismymicrowaveleaking.isotropic.us) |
Hint: If you're ever doing radio work in the field and need an instant Faraday cage a microwave oven is a good candidate. Turn the power off first to reduce the risk of accidentally irradiating your device, but leave it plugged in to get an earth connection to the shield. (This is how I know an LTE connection can be maintained in a microwave oven.)
Since your WiFi signal, however is almost exactly the same and there are many apps that will show and record signal in dB (as described in TFA). You could measure while the door open/closed if you're really careful not to turn it on. The lithium battery fire could respond very badly to water!
https://www.nrl.navy.mil/STEM/LEctenna-Challenge/
I stumbled across this little project a few weeks back, ordered the parts (just a diode and an led), and it works. Put a bowl of water in the microwave (or dinner), turn it on, then wave the lectenna around the cracks and see where it lights up.
I originally found the lectenna by researching if it was possible to power an LED wirelessly by leeching power from a house 60Hz line. I haven't made any progress on that, so if you have ideas I'd love to hear them.
For the safety's sake, might be nice to also recommend to unplug the microwave oven altogether as the first step.
[1] https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-cont...
I think you're vastly underestimating how little people know. A friendly FYI: seems you're in some kind of a bubble.
Personally I didn't learn about don't-microwave-metal (incl phones), until I was about 20 -- and at that time, I had already been studying physics at university for a year, and knew vastly much more than what most people ever will. I wouldn't say I was a child, at that time.
Be happy if people in general realize that photons and coronavirus aren't the same thing, although they're both small.
Edit: actually there's an example of an unexpected mistake in this thread already, in the comment by hanoz. As mentioned before, listing unplugging as the first step would be useful.
I kind of doubt an independent inventor could bring this to market with today's startup climate.
Agreed. I just tested with two phones and one phone timed out but the other was able to maintain a connection. That would suggest that my microwave is maybe leaking. However I'm able to use the microwave without any noticeable effects from on 2.4ghz devices.
I went ahead I tried it with a 5GHz connection (the site was practically begging me to) and it turns out my microwave blocks both 2.4 and 5 GHz signals. Pretty cool! If your wondering, it's a decade old Sunbeam that I bought for $30 so nothing special.
https://youtu.be/DCYrrNQc3lM https://youtu.be/6N3P842Nay8
Whether your phone can connect from inside is not a great standard. Your phone's antenna is maybe 1/100,000 the power of a microwave oven magnetron.
Might be nice to expand on "will not work". Wouldn't 5 GHz Wi-Fi failing to connect show that it's even better at blocking, and would easily block 2.45 GHz too? And I'd think that they should block 5 GHz too, since those meshes look quite fine, and they probably try to be extra-safe.
However I do agree that it's probably still gonna work because the faraday cages on microwaves are always overkill (even the cheap ones).
In this case it could be the opposite: faraday cages only work for blocking wavelengths that are longer than the wavelength that it's designed for (presumably 2.4ghz). Therefore it could be blocking 2.4ghz but letting 5ghz waves through because it's too small to contain.
It’s interesting the browser can get access to this information with no prompts
Exactly what information is it getting ? What Chrome API is this using ?
note: do not turn your microwave on for ANY portion of this test
1. Unplug the microwave.Pretty sure you need the earth though right?
But one could also use fridge for this test.
Funny how kitchen stuff was thought to be women's work once.
Clarification: domestic kitchen stuff was thought to be women's work, professional kitchen stuff was thought to be men's work (and still is[1]).
Unless there's a leak, then the chart continues updating while the phone is in the microwave.
Then open the door and look if it could/couldn't keep pinging the server while the door was closed.
(A microwave is ~1 KiloWatt up close, WiFi is ~1Watt and meters away. This is like spreading fear that your house has a warm radiator which is bad because ovens use warmth to cook food).
This basic information is contained in the first very short paragraph of how a microwave oven works on wikipedia.
[1] https://en.wikipedia.org/wiki/Microwave#Effects_on_health
Especially the kind of inventor who created microwaves for experiments with reanimating frozen hamsters, cough James Lovelock.
(Tom Scott's video "I promise this story about microwaves is interesting" which includes a brief interview with James Lovelock last year at age 101 - https://www.youtube.com/watch?v=2tdiKTSdE9Y )
Also, unless your electrician had a catastrophic fuck up, the metal cage will never be at live voltage, with or without grounding.
You might take apart a microwave oven and discover that there are actually several pieces of sheet metal in them. Expensive ones connect them by staked wires. The capacitor is usually rated for 2000 volts and it packs quite a punch.
It's the metal grid in the window (with holes smaller than the wavelength of the microwaves), and the metal shell of the cavity, not any "plastic." The same reason the metal grid works is why there doesn't need to be a perfect door seal. As long as as the gap is smaller than the wavelength of the microwaves, it's fine.
> Also, it seems that the outer metal shell of the device forms an active part of the circuit, so if it isn't plugged into a grounded outlet it sits at lethal potential.
The shell doesn't sink RF, it reflects it. GFCI outlets (required in many areas for kitchen outlets) trip at 5mA differential between hot and neutral. No appliance is designed to sink current into ground unless there's an electrical fault.
> Then there is beryllium oxide in the thing...
Beryllium oxide hasn't been used in microwaves for a long time, and it presents zero risk unless the magnetron is smashed.
Recommended reading for you:
https://www.dannyguo.com/blog/my-seatbelt-rule-for-judgment/
https://www.psychologytoday.com/us/basics/dunning-kruger-eff...
Edit: They can interfere with WiFi because a microwave could leak a tenth of a percent of its nameplate power and it would overpower your access point by anywhere from 1x to 10x. Access points can, on certain bands, have radios up to ~1W, but 125-250mW is much more common.
It would also be completely harmless even if you were standing inches away from whatever the source of the leak was. Microwave RF energy only becomes dangerous when it is strong enough to heat up parts of your body that cannot cool themselves quickly due to having little/no bloodflow, like your eyes.
You could put a parabolic antenna on your home wifi AP and standing in that beam would expose you to more RF energy than your microwave.
I don't know why HN suddenly has a "DANGERS OF MICROWAVE OVENS!" boner this week...this is I think at least the second article on the subject of the 'dangers' of microwave ovens.
Regarding "the door gap is a long line" - that would be relevant if the beam were aimed parallel (or close to parallel) with the gap...
In other words, why is microwave leaking worse than e. G. My oven leaking heat? Is potential small amount of microwave radiation In some specific way worse than feeling the heat when you open the oven after baking? I know radiation is a scary term but what is the real actual scientific documented risk here?
I know some pregnant families paid more money for microwave tests than their microwave costs and it never felt legit but I could be wrong.
The issue is the gap in a door normally forms a long line.
The fact they interfere with WiFi should make it obvious the average microwaves faraday cage is far from perfect.
Edit: okay maybe I can imagine you’re saying that women have been competent in the kitchen and men [/other gender identifying people?] have demonstrated not being as competent. I’m really trying to stretch credulity to read this in good faith.
There really isn't any substitute for a proper EMC chamber.
I'm sorry, but I really cannot follow your logic here.
Sexist? Please, shove that word. This is simple facts about life.
Respectfully, fuck no.
Note: I'm a past master at destroying old electronics in my microvave (this way I can't change my mind later and then not throw it out).
About three seconds is all it takes (just time for the magnetron filament to warm up) - any longer and the stuff starts to stink from the heat. There's no second chance if you make a mistake.
I've been known to change my mind half way through destroying something when I think of another use for it - the microwave method ensures that the part of me that doesn't like throwing out electronic things that still work always gets thwarted.
The idea of microwaving electronics came to me a long while ago for very different reasons. In the early days of microcomputer control systems I used to work with Intel Multibus computer systems (these are so old you better check this Wiki out to know what I'm talking about: https://en.m.wikipedia.org/wiki/Multibus).
In those days Multibus boards were hellishly expensive and we used quite a lot of them. If one went faulty then we either fixed it at board level or if it failed within the warranty period then we returned it to the agent who then had it fixed (boards were always repaired - never thrown away).
Anyway, one board we received had an intermittent fault and I had it returned under warranty and the agent supposedly fixed it and returned it but it was still intermittent (you know, it had one of those annoying intermittents that was rare enough for one to think the problem was fixed when it wasn't). This toing and froing to the agent occurred at least three times and the problem still wasn't solved so I put an end to it by putting the board in the department's lunchroom microwave.
The plan was to damage a sufficient number of ICs to render the board beyond economic repair (BER) but not make the matter of microwaving it obvious to the supplier. This was very successful, a new board with a different serial number was supplied and the intermittent problem disappead.
To accomplish a truly defective board without obvious signs of user 'abuse' requires some care. The aim is to provide just sufficient microwave energy to puncture or short-circuit the junctions in the ICs but to not make it obvious (in practice, about one second of RF is needed to accomplish this).
Excessive RF will heat the silicon to the point where it boils the ICs' encapsulating compound and one ends up with little craters in the middle of the ICs which make it obvious the board's been zapped.
Most microwave ovens take about 3 seconds before any RF appears (no RF will appear until the magnetron cathode is hot enough to become emissive), so it's important to calibrate your oven before embarking on such an exercise.
I've used this technique very effectivly a number of times over the years. I must mention another incident long after the first, however this one had nothing to do with Multibus.
It involved a setup jig for programming certain electronic equipment and its motherboard was about as complex as a Multibus one. When motherboards failed I either fixed them or returned them to the manufacturer's repairer who was in a third country (he was renowned for fixing dead boards that people like me considered BER).
Again, we had an intermittent board that had crossed the oceans a number of times and it was still intermittent so I finally gave it the microwave treatment and returned it to him. Right, this silly bugger actually wasn't going to let it defeat him, he returned the board to me with a message to the effect 'this was a very problematic board, I had to replace about half the ICs [about 50 total per board], seems it was hit by a lightening surge'. Well, the board worked - sort of - but it had new and different intermittents (presumably, some of the ICs he'd not replaced were suffering breakdown puncture in their SiO2 insulation and thus were experiencing partial failures).
I returned the board again without any extra zaping and this time it was replaced with a different one (presumably, he'd either given up on it or wasn't prepared for my wrath when or if it failed again).
BTW, one can get pretty good at this if you calibrate your microwave carefully. Such zapping should never exceed nuking more than about 25% of the ICs. This is usually sufficient to deter most diehard repairers whilst not drawing their attention to the actual cause of the failure.
Why should it be grounded?
The cell signal in the Faraday cage causes a mirror signal on the cages inner surface and the cage’s conductivity ensures that the potential is zero elsewhere in the cage.
Why do I need the ground? Is it a consequence of not having a perfect conductor?
Also, if that were the case, an airplane couldn't be made into a Faraday cage.
Also, the cage+Earth system would itself be an antenna.
If you need ground for a topologically imperfect cage, maybe… but I doubt it.
I think (but I don't know!) this is like the legends surrounding engine torque car guys believe. Electrical engineers putting everything to ground because they got burned
It would take far too long to heat up hot enough to cause more than skin burns and nobody would ever stand there long enough to even get a skin burn to begin with. Any sink presents a much more serious risk of injury than a broken microwave. A hair dryer is more dangerous.
It seems like you might be extrapolating the speed of heating some piece of food and assuming it could possibly heat someone outside of the microwave at the same rate. It can't. The only reason small things heat up quickly is because in a closed microwave the walls reflect the microwave energy many many times before it's eventually absorbed by the food. It's a high Q factor resonant chamber. Effectively when there's little energy being absorbed or escaping the intensity of the microwave radiation is multiplied many times over until the energy being absorbed is equal to the energy being put in. If the door is removed it's just going to bounce out and you get none of the massive jump in intensity that you get with the door closed and only a small 1/2 lb of food inside.
Nuking your phone in the microwave is in the same category as baking it in the oven. You really shouldn't be surprised when you don't have a working phone anymore.
I don't think it is wrong of us to expect better from a bunch of adults. They should know better.
It doesn’t matter one bit whether you think someone should think it through the way you would. People routinely disappoint on that front, and it’s almost always because people have expectations that are closer to their own experience and thought process than they realize.
Personal anecdote, for your judgy amusement: a couple weeks ago I fell hard on the pavement of a very busy arterial road. I was running behind schedule, hurriedly looking for a chance to beat the crosswalk signals if there was a safe gap in traffic. I was paying attention to the height of the curb as I went, because it’s unusually high off the road at one intersection then gradually gets closer to a normal height in the course of a block. Trouble is, I wasn’t paying close enough attention, and I misjudged the height by about a foot.
I stepped into the road in a gap in traffic, but there wasn’t anything under my foot when I stepped down. Before I know it, I was sprawled out on the street, gratefully with a busted up hand not a busted up head. And more gratefully, with an audience sitting at the next red light, not still traveling towards where I fell.
I was, indeed, embarrassed by all of this. And any one of the people who saw it happen surely could have called me stupid. Maybe they even did, but I’m happy they kept it to themselves at the time. I realized my error as soon as it happened. What good would have come of insulting me on top of that?
There is an idea floating around that all judging is bad. I reject that. It might not be helpful to the person being judged an idiot, but the expectation that I should change my view of others to help them with their learning is... I'm struggling to find the right words here... an imposition?
I think it is the difference between being kind to everyone and not being unkind to anyone.
Everyone judges people all the time, to claim otherwise is a lie. I will continue to judge people by their actions, whether or not they improve by some metric is not my aim, nor my problem.
Anyway, I don’t recall all the details but 1W from a microwave is probably an underestimate.
WiFi uses multiple separate frequencies and outside of what a microwave should be producing. So it’s significantly more energy to block it than you might think especially when the hub is closer to the device than the microwave.
PS: To be clear this is still a trivial amount of energy, just annoying when reheating food blocks WiFi.
So you were off by a factor of 200, and you can see that my referencing -40dB of attenuation was an underestimate. I do wonder what details it was that you thought you might recall.
Quite disappointed by HN standards of self-moderation yet again.
In fairness I was surprised to learn that nerve cells absorb a fair bit more than skin and fat leading to quicker nerve damage. All things considered though, I stand by my statements, hot water at a sink presents a much bigger risk given the frequency of exposure and the risk of burns.
A 1 foot cube, has 6 faces of ~30 cm * 30 cm or 5,400 cm2. 5,400cm2 * 5mw = 27 watts. Of course 2 inches from the surface is a significantly larger box.
Of course that’s a legal maximum, most devices should be well below it.
Anyway, math is math but presumably this is why that’s the legal limit. It’s low enough to be safe while high enough not to be expensive for manufactures.