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My mother-in-law recently got me interested in checking the EMF levels of my home using an Extech Instruments 4800836 3.5GHz EMF Meter. It seems the standard safety level is 2.5 mG EMF, while Sweeden suggests a safety level of 0.25 mG. The problem I'm having is the output on the device I'm using is in mVm and Vm (volts per meter) respectivly, but all the dangerous readings are measured at mG! mG is a magnetic field, mVm is voltgage. I've scoured the internet, but failed to find any explanation as to how much Vm is dangerous, or if there is a Vm to mG conversion table (doubtful). Yes, I read the guide for the device, but it didn't tell me what I wanted to know. Maybe I'm asking the wrong question. Anyways, if anyone here know any data that might be useful, I'm all ears
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"The true value of a human being is determined primarily by the measure and the sense in which he has attained liberation from the self." -Albert Einsetin
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01-05-2012, 12:32 AM
(This post was last modified: 01-05-2012, 12:41 AM by Concillian.)
I must be in real trouble.
I hang around unshielded electromagnets that produce 1000 - 5000 Gauss fields all day long.
One of the guys I work with has been working feet from these kinds of magnetic fields for 35 years. I guess he's going to die soon... but then again most people who have been working for 35 years will die "soon" (of old age).
just so you know, the above is true, but in relation to the topic, just in jest, since the frequencies of the fields I deal with are nowhere near RF frequencies.
Anyway. Gauss is magnetic field density and mV per meter is electric field strength... These are different things, which is why you aren't finding a conversion.
The meter should also have a magnetic field strength measurement. Which, of course is probably not in convenient units like Oersted <...checks manual for your device...>. Indeed, it's in Amperes per meter.
Oersted is the measure of magnetic field strength I'm most familiar with and most sane people work in, since 1 Oe = 1 Gauss if permeability is 100%. Makes things easy... everyone likes easy. I'm pretty sure the body is pretty close to 100% permeable, so that gets you to Gauss if we just convert Amperes per meter into Oersted:
<insert google-fu>
and apparently that is 0.004 * Pi or 0.0126.
I should clarify that I deal with the scientific side of these magnetic fields, and I've encountered "unconventional" conversions between incompatible units in safety regulations, so there may be some other way that the safety guys do this. I've only done the obvious conversion of like units to get to Gauss. There may be some weirdness that the safety guys do to take into account the electric field effects as well.
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Very cool. Ill give it a try tomorrow. Sleepy time now.
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(01-05-2012, 06:40 AM)Taem Wrote: Very cool. Ill give it a try tomorrow. Sleepy time now.
Not to be picky but it has to be mV/m (mVm is something else).
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(01-05-2012, 08:41 AM)eppie Wrote: Not to be picky but it has to be mV/m (mVm is something else).
Or many. e.g. Merck Veterinary Manual, Market Value Margin, Million Vehicle Miles. I like m&m myself.
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(01-05-2012, 08:41 AM)eppie Wrote: (01-05-2012, 06:40 AM)Taem Wrote: Very cool. Ill give it a try tomorrow. Sleepy time now.
Not to be picky but it has to be mV/m (mVm is something else).
Indeed. Lets see in my office at sitting distance (not dirrectly behind the computers or anything), I've got 3.0 V/m, 8.0 mA/m, 24.8 mW/m2 (<-not sure how to display to the second power in ASCII), and 2.4 u W/cm2. I have no idea how to figure out the Gauss. Based on what Concillian suggested, I believe I take the total amps (which should be mA/m), and multiply this by 0.0126 to get a approximate conversion, which would be 0.1008 mG. Does this seem correct? Or do you think I'm doing this horribly wrong?
"The true value of a human being is determined primarily by the measure and the sense in which he has attained liberation from the self." -Albert Einsetin