Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

EMF query

Status
Not open for further replies.

atl11

Electrical
Dec 21, 2007
3
AU
Hi,

i just bought a couple of emf meters for experamentation. I walked around my house and noticed mid to high levels(around 8mG)in most parts of the house especially all over the ground even when no electrical aplliance were on?? Does anyone know what this could be caused by?

Thanks.
 
Replies continue below

Recommended for you

Does the meter distinguish between DC & AC, and AC by frequency?

According to Wiki(*) the "...earth's [DC] magnetic field is 0.5 gauss, ...a small NIB magnet is about 2,000 gauss..."

*
8mG is of course 0.008G, which is next to nothing.

For comparison on an AC scale, turn on your stove top electrical burner element and probe the magnetic field above it. Be very careful not to burn yourself (use common sense). You can repeat the test holding a small powerful magnet in your hand (instead of the meter) to put the relative values into perspective. The magnet will vibrate inside your closed fist. If you hold it just right, you might even get it to oscillate violently in the open space inside your clenched fist.

Given the relative rarity of 'Cancer of the Right Hand' amongst people that prepare hot food, it is safe to conclude that the link between EMF and health is very (very^12) weak.
 
Those meters are usually (always, I would say) coil based and react only to AC fields. So, it is probably just that you see. 8 mG corresponds to .8 micro-tesla. That is a lot lower than most OSHA recommendations. I think you have 60 microtesla (600 mG) for the head and 300 microtesla (3000 mG) for body and legs as a limit in most states in the US. And there is not much evidence (none, actually) that even fields of that strength are harmful.

Gunnar Englund
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
 
I am not to sure. I bought the Cellsensor and Electrosensor from:
They say an average level exposure (found on most sites) is around 1mG a day. This is slightly freaking me out a little, when i use it near electrical items like air conditioner lights etc, it reads what i thought it would (around 15mG up close) but i dont understand why i am getting these same values in places where i dont think this is emf . I dont live near power lines dont use wireless transmitters etc.

I found this site:


Being an engineer i AM sceptical about his stuff but who knows. I am not to sure what to do.
 
It is an instantaneous value, not "a day".

Did you try it above your stove? It would be interesting to see what sort of value you get there. Don't burn yourself, just switch it on and grab the reading before it gets hot.

The field won't do you any harm, but the worrying ("...freaking me out...") will take years off your life.

To answer your question about why you're seeing 8mG instead of something less, perhaps you could take the gadget for a walk to a large empty field (far far away from anything) and see what it says. If you still get 8 then perhaps the instrument isn't working correctly. See if you can get a zero somewhere.

Another explanation is offer by the seller: "Any questions about relating emf readings to spirit activity? Not a problem, Email us with your question." So perhaps you've got eight milliGhosts.

Excuse the joking around, but my only problem with living near power lines would be that they might cause static noise in my ham radio.

 
Dear atl11.

You have been had.

The electro-magnetic field scam has been going on for decades. Very extensive research has been done by authorities all over the world and there is no evidence at all that magnetic or electric fields from power lines, hair dryers, electric clocks, micro-wave ovens - or whatever happens to be your concern - has any effect on human or any other biological organisms.

I have been working with heavy electric motors and transformers all my professional life (started with ASEA, now ABB in 1961) and if there would be any problem at all with these things, I should have noticed. There are work-places where the exposure is around 60 microtesla (600 mG) and has been so for decades. People work 24/7 there and no health problems have been found.

I have visited those sites that you refer to. They are typical superstition sites. The first one has "ghost" in the name - which says something about it. The second one is doing stone and gem therapy - which says something about them, too.

If you want to be had in a straight and open way, then buy Snake Oil. If you want to pay scam artists, then go on worrying about harmless magnetic and electrical fields. The worry will, as VE1BLL points out, reduce your life and your life quality a lot more than even the strongest magnetic field.


Gunnar Englund
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
 
Jeez, one site that looks for "spiritual" activity, and the other, using "sacred geometry" and "crystal catalyst" techology. They may, or may not be wrong, but certainly, they're unreliable as honest, scientific sources. You migh as well go looking for a banker in Burkina-Faso.

As for bees and cell phones, most of the die-offs are in RURAL areas, and guess what, there's VERY limited cell coverage, so where's the smoking gun? I'd hardly consider ABC news as an authoritative source of science news. Popular Science would rank higher.

TTFN

FAQ731-376
 
Yes i guess you guys are right, it is strange though that there are so many studies that can be found on the net about powerlines etc and health with studies showing there are links and studies showing no apparent link. This really confuses the public but I agree there is no point worrying about it.
Thanks for your help.
 
Not strange at all. Lots of misled environmentalists produce "research reports" that are complete non-sense. And then again, there are some reports where the correlation is weak, sometimes non-existent and sometimes negative. Guess what reports are picked by those who make money on scaring people with EMF? Those reports that show some correlation, of cause.

This phenomenon is called "Biased selection" and makes it look like there really is a problem with magnetic fields. As I said before, better buy some good Snake Oil.

Gunnar Englund
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
 
I worked on a GE MRI at a hospital which has a huge DC field (1.2 Tesla) and the MRI technicians say that their health seems to be better since they started working at that job due to the magnetic fields.

A DC magnetic field align the spin of the atoms in your cells so they all spin in the same plane (though not all in the same direction)

Magnets are sold for healing purposes.

There are lots of lazy people out there that just make up crap and sell it.

I've seen a crystal to remove the bad microwaves from your microwave oven to make your food taste better. That's my favorite one so far.

kch
 
1.2 Tesla, that's 12,000,000 mG. Twelve million milligauss. Just to put things in perspective.


Gunnar Englund
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
 
When I was at school EMF meant electro-motive force,

Who is the clown that hijacked EMF when they meant
EM fields? and since they could not get their terminology right am I supposed to believe them?

We seem to live in a world where things are nothing unless they have a nice easy bull s*** buzz word title, usualy one that used to mean something else and it is getting very confusing at least to me.
 
There's nothing nefarious or inept about it. The bottom line is that everyone wants to use TLAs instead of typing them out, and the overlap isn't just with stuff in the same industry. Look hard enough, and you'll find piping acronyms that look like EE acronyms..

TTFN

FAQ731-376
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top