Testing a microwave for leaks

Discussion in 'General Electronics Chat' started by cmartinez, Mar 30, 2016.

  1. cmartinez

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  2. wayneh

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    Not too hard, apparently.

    http://www.amazon.com/s/?ie=UTF8&ke...vptwo=&hvqmt=b&hvdev=c&ref=pd_sl_5qvlhtlapg_b

    I'm not buying that "life hack", BTW. If someone could calibrate it and prove it works, maybe. But cellphones aren't even all on the same frequency, and none of them is using microwave frequency.

    But more importantly, a microwave might be making 1kW of power. A leakage of 0.1% - 1W - would be huge I think. I bet my phone would not receive a call if the signal is knocked in half, let alone by 3 orders of magnitude.
     
  3. cmartinez

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    And apparently, there's a huge pricing range between devices. As low as a few bucks, all the way up to $500.00!
    This means that either the consumer is being abused, or the devices have a very large quality gap. Most likely the former.

    Check this so-called "DIY test-kit", for instance One of the comments states that the "detector card" is nothing more than a piece of plastic with temperature-sensitive ink!.
     
  4. alfacliff

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    I use a simple rf detector here ar work, a germanuim diode across the probes of my fluke meter set to dc volts. near an rf field, it indicates a few mili]volts to several volts..this circuit is called a "field strength meter." i used to work on radar for rca avionics, this would let me know if someone was running a radar to close to me,.
     
  5. RichardO

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    A co-worker said that he kept a neon lamp voltage detector in his pocket when repairing radars sets in planes. If the lamp came on the he got the h*** out of there.
     
  6. wayneh

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    Actually that seems like a pretty good idea. I was thinking you could probably detect a pretty small leak with your bare hand run around the edge of the door. If you can't feel it, who cares?
     
  7. ian field

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    The clear fluid protein in the eyeball cooks *MUCH* easier than the flesh on a hand.

    That's basically what cateracts are.

    There are various internal organs whose physical size makes them very efficient antennas.
     
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  8. #12

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    Amana issued me a field strength meter in 1973 for the worry-warts who bought an Amana Radar Range and then worried about it. No customer ever asked me about leakage, but I learned a bit. Every microwave oven leaks a little at the corners of the door gasket. Four inches reduces the measurement by about 90% and 12 inches reduces it to un-measurable by the probe I had.

    ps, I love the neon bulbs for voltage detectors. I diagnosed many a TV by waving an NE-2 bulb (taped to a plastic stick) near the high voltage section. In those old tube sets, you could tell a lot just by looking at the colors on the tubes and using a neon bulb.
     
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  9. GopherT

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    The original method was a Hershey bar in a shirt pocket.
     
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  10. cmartinez

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    Interesting... I once used fluorescent light sticks to calibrate the antennas and test the emission strength on those old CB radios... whatever happened to them, btw? are they still around?
     
  11. GopherT

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    Fluorescent tubes - yes
    Antennas - yes
    CB radios - yes (check at any truck stop or walmart).
     
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  12. RichardO

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  13. ian field

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    Years ago, there were several published projects for microwave leak meters - they seem to have tailed off in recent years. Most were just a PCB track dipole, a germanium diode, a 1nF cap and a meter movement.

    The bought item was potted to stop me looking what's in it.
     
  14. debe

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    This is a Kit I built many years ago & found it was quite effective when repairing & testing microwave ovens. It doesn't work with Marine radars
     
  15. shortbus

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    Seems my thinking was off when I saw the thread title, "testing microwave for leaks". I was going to suggest, hold it under water and look for bubbles. :)
     
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  16. cmartinez

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    ... and apply a pressed hot patch where necessary ...
     
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