emf problem

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Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
all fun aside. Every time we investigated a sizable EMF problem ( 30mg would be considered sizeable from some labs) and a person who felt some sort fo discomfort we actually did find issues where the person complained. We located the source made the repairs and the customer was satisfied.

The issue that Trouyano has could be a problem with the neigbors ground or that of the transformer. I have seen transformer grounds removed by landscapersand such. Dielectrics installed by plumbers. This could leave a bldg essentially ungrounded.
 

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
080710-1155 EST

Sierrasparky:

To get 30 mG at 1 meter from a single wire requires 15 A. If go away 5 meters, 200 inches, then this drops to 6 mG.

How do you get single wires with this kind of current? Most likely thru the water line serving as a neutral for your neighbors. In this case the water line is the single wire and there is no close by conductor with current flowing in the opposite direction to cancel (reduce) the magnetic field from the single wire.

Was the person with a problem actually exposed to 30 mG? If you took this person and ran a controlled experiment could you really prove that 30 mG had an adverse effect on them? This kind of experiment would mean that the subject had no way of knowing when they were being exposed to the field or not.

.
 

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
080723-1615 EST

Trouyano:

What measurements did you make with the cheap meter and do you have the better meter you ordered? What is the cheap meter resolution?

What milli-gauss values did you read and how did the values change as you moved away from the assumed source? Of course mG units imply magnetic field flux density.

What were the lowest and highest readings you found?

In my house in most areas I am below 0.05 mG. Same in my backyard. Currently my instrumentation has a noise level of 0.05 mG.

My water supply line has between 55 and 110 MA of current flow. Looking for this water line thru the basement floor I get a reading of about 0.1 mG and some of this reading results from instrumentation noise.

.
 

SegDog

Member
Location
Philadelphia
on a more serious note...

on a more serious note...

I really appreciate the posts by gar and stepke (and others). It's a pleasure to read clear, intelligent and thought-provoking technical information. Please, continue to post often.

When I bought my Gauss-meter, it came with a full-cover "tin-foil hat". No single point for entry. As Marc has stated on a different thread, this world's gone totally bonkers. With as many people as we have talking on the cell-phone incessantly, it won't be long before the effects of EMF show-up as brain disease. I understand that there are documented cases.

YHS
 

cschmid

Senior Member
emf oh no...all kiding aside we need to look at both sides of the story including the governments opinion..

http://earthcalm.com/pages/main.php

http://www.who.int/peh-emf/about/WhatisEMF/en/

http://www.osha.gov/SLTC/radiofrequencyradiation/electromagnetic_fieldmemo/electromagnetic.html

http://www.osha.gov/dts/hib/hib_data/hib19900207.html

http://www.osha.gov/pls/oshaweb/sea...ilter=SLTC_STATIC&p_status=CURRENT&p_logger=1

Trouyano in the last link there is some info you can use when dealing with this situation..

Now if that is not enough reading for today let me know..text me in the crestliner maybe I can find time to release the ugly stick to respond..:grin:
 

teslagood

Member
Go get yourself a Hewlitt Packard RF spectrum analyzer hook up any old crappy antenna ( not cut to any particular wavelength ) and look at the spectrum from about 20 kHz-1gHz. You will see all kinds of RF energy flying around and through your customer's or anyone else's house.

That's the world we live in pal. The sky ain't falling.
 
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