microwave leakage

Chocolate.

Butter.

milo

Bacon.

Does Any one know about a chemical which can be used as a sensitive detector

for microwave radiations leakage - 08/04/08

A number of chemicals react to microwaves particularly hydrocarbons. However, at microwave levels corresponding to typical leakage levels the number of number of molecules involved could be nil. One would require an extremely sensitive gas detector or mass spectrometer. The measurement is difficult and the equipment very expensive.

Now the leakage level from the microwave oven is normally very low compared to 1 milliwatt per square centimeter. If the door seal has significant damage or the seal is very dirty then one could detect some small fraction of that noted above. If one treats the radiation site as a point source then the leakage level falls off as 1/(R squared) thus the level is greatly reduced even at a relatively small distance R from the source.

I note that two other discussions indicate candy, butter, and bacon as possible detector agents. Candy is interesting in that during WWII the US magnetrons were tested and "aged" with the magnetron output feeding the room air. These magnetrons could have been radiating between a few hundred and one thousand watts of average power. It is told that Dr. Percy Spencer who headed up the Raytheon Microwave Tube Division noticed one day that a candy bar in his pocket had melted after he passed by some of these radiating magnetrons. This led to the Microwave Oven; an interesting story.

I suspect it would be very difficult to separate out any heating effects due to microwaves from other possible heating causes. Perhaps run some tests on the above items using the sun's radiation (1000 watts per square meter; 100 milliwatts per square centimeter) and then attenuate the radiation via say plastic sheets. Use a light meter to determine the levels of incident radiation on the item. Might have to shield the item from wind, etc. and try different support materials as copper, aluminum, wood, plastic, etc. to try to pin down external heating effects.

Microwave radiation detectors do exist; again, quite costly. You might search the microwaves/electronic equipment surplus houses.

A number of years ago I located a small, hand held, inexpensive unit (Microwave Leakage Monitor) made in Taiwan. No manufacturer indicated. Two scales each having a range (green –safety; red-caution). The dividing line could be either 1 or 10 milliwatts per square cm.

Check for Hewlett-Packard coaxial detectors for input power vs. voltage output. Use the detector as a probe. Connect a 50 ohm coaxial line to the detector input. Strip away the outer conductor and dielectric at the end of the cable leaving the center conductor bare for about ¼ inch; the cc will pick up an electric field; if you make a loop (about ¼ inch diameter) by bending the center conductor and soldering it to the outer conductor; the loop will pick up the magnetic field. Display the output voltage on a scope. Scan the door seal for fields.

TOMR