EMF Detector made easy?

B

Bryan

Guest
Hello one and all.

I have been looking into building a "very" sensitive EMF detector due to
issues with power lines in the area. I am sorry to say that I have no REAL
idea on how to do it.
I was also told that there is a way to build a device that would use Hall
effect sensors to measure the earths magnetic field. It would be much more
sensitive and would work if adjustable. I have yet to find a circuit design
that will give a visual as well as audible measurement. An LED bar graph
would be ok.
Any good ideas on what I could build that would do this?

Thanks for your help.

Bryan
 
"Bryan" <abel6479@cox.net> wrote in message
news:eNk_d.14802$Fy.5619@okepread04...
Hello one and all.
Greetings, one.
Click to expand...

I have been looking into building a "very" sensitive EMF detector due to
issues with power lines in the area. I am sorry to say that I have no REAL
idea on how to do it.
Click to expand...
Then perhaps you have no real idea of the
potential hazard, and rely on the morass
of conflicting, often misconceived studies
as the basis for deciding there is an issue.

I was also told that there is a way to build a device that would use Hall
effect sensors to measure the earths magnetic field. It would be much more
sensitive and would work if adjustable. I have yet to find a circuit design
that will give a visual as well as audible measurement. An LED bar graph
would be ok.
Any good ideas on what I could build that would do this?
Click to expand...
If I wanted to do that, I would probably use a
simple coil pickup, followed by a high gain semi-
narrowband 60 Hz filter in front of a PIC's or uP's
A/D input, then implement a much narrower filter
using DSP to pull what is likely to a small signal
out of the noise.

It would be easy to create any display you like
using software and one pin per LED or even
multiplex LEDs to drive more of them. For,
example, at 1 nanoTesla, the red light could
blink gently. At 1 microTesla, the bar would
be fully on and blinking omenously. At higher
levels, you could spell out "Run for you life!",

Thanks for your help.
You are welcome.
Click to expand...

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.
 
On Thu, 17 Mar 2005 12:21:45 -0700, Bryan wrote:

Hello one and all.

I have been looking into building a "very" sensitive EMF detector due to
issues with power lines in the area. I am sorry to say that I have no REAL
idea on how to do it.
I was also told that there is a way to build a device that would use Hall
effect sensors to measure the earths magnetic field. It would be much more
sensitive and would work if adjustable. I have yet to find a circuit design
that will give a visual as well as audible measurement. An LED bar graph
would be ok.
Any good ideas on what I could build that would do this?

Thanks for your help.
Click to expand...
I'd say that if they're too low to detect except with specialized ultra-
high sensitivity equipment, you're blowing smoke up your own ass.

Cheers!
Rich
 
"Larry Brasfield" <donotspam_larry_brasfield@hotmail.com> wrote
in message news:65l_d.31$zO.1051@news.uswest.net...
"Bryan" <abel6479@cox.net> wrote in message
news:eNk_d.14802$Fy.5619@okepread04...
I have been looking into building a "very" sensitive EMF detector due to
issues with power lines in the area. I am sorry to say that I have no REAL
idea on how to do it.
[System approach using uP cut.]
It would be easy to create any display you like
using software and one pin per LED or even
multiplex LEDs to drive more of them. For,
example, at 1 nanoTesla, the red light could
blink gently. At 1 microTesla, the bar would
be fully on and blinking omenously. At higher
levels, you could spell out "Run for you life!",
Click to expand...
Just to help promote this approach ahead of
the other (as yet unseen) contenders ...

With a little extra complexity in the coil and a
few switches, it could also provide an arrow to
indicate which direction the irradiated user ought
to run. Otherwise, given the usual arrangements
in the vicinity of power lines, he might run without
gaining any *real* benefit from the effort.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.
 
Gosh Rich, thanks for the insight!
What a pal!
"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.03.17.21.06.28.854635@example.net...
On Thu, 17 Mar 2005 12:21:45 -0700, Bryan wrote:

Hello one and all.

I have been looking into building a "very" sensitive EMF detector due to
issues with power lines in the area. I am sorry to say that I have no
REAL
idea on how to do it.
I was also told that there is a way to build a device that would use
Hall
effect sensors to measure the earths magnetic field. It would be much
more
sensitive and would work if adjustable. I have yet to find a circuit
design
that will give a visual as well as audible measurement. An LED bar graph
would be ok.
Any good ideas on what I could build that would do this?

Thanks for your help.


I'd say that if they're too low to detect except with specialized ultra-
high sensitivity equipment, you're blowing smoke up your own ass.

Cheers!
Rich
Click to expand...
 
Someone wrote:

Hello one and all.

I have been looking into building a "very" sensitive EMF detector due to
issues with power lines in the area. I am sorry to say that I have no
REAL
idea on how to do it.
I was also told that there is a way to build a device that would use
Hall
effect sensors to measure the earths magnetic field...
Click to expand...
Google "Fluxgate magnetic"


-Robert Scott
Ypsilanti, Michigan
 
"Bryan" <abel6479@cox.net> wrote in message
news:eNk_d.14802$Fy.5619@okepread04...
Hello one and all.

I have been looking into building a "very" sensitive EMF detector due
to
issues with power lines in the area. I am sorry to say that I have no
REAL
idea on how to do it.
I was also told that there is a way to build a device that would use
Hall
effect sensors to measure the earths magnetic field. It would be much
more
sensitive and would work if adjustable. I have yet to find a circuit
design
that will give a visual as well as audible measurement. An LED bar
graph
would be ok.
Any good ideas on what I could build that would do this?

Thanks for your help.
Bryan
Click to expand...
It's not difficult to build, you an use a ferrite loopstick with a lot
of fine wire wound on it as the sensing probe. One of these is here.
http://www.zen22142.zen.co.uk/Circuits/Misc/emf.htm

Here's a meter using Hall effect sensors.
http://my.execpc.com/~rhoadley/magmeter.htm
http://my.execpc.com/~rhoadley/magmetr1.htm

The big difficulty is calibrating it to a known standard. And they are
not that expensive so there is no point in building one yourself.
There are several companies that offer a calibrated EMF measurement
meter for under a hundred dollars. Here's one with LEDs for under $25.
Also the cellsensor mentioned below. http://www.lessemf.com/gauss.html
Here's their main page
http://www.lessemf.com/

Two other inexpensive meters mentioned in a paragraph from a story found
with google:
"I brought an am radio to the office and it would be very noisy in that
office but not in the other rooms and really bad near the wall and
ceiling. I then went out and bought an emf meter (cellsensor, analog
meter, single axis, $42.00) and measured very high readings only in that
office and the hallway. It would blink and beep like crazy even on the
high setting. I did much research and talked to other engineer friends
who tell me it is unconceivable to have that much emf. So I bought a
digital emf meter (A.W. Sperry EMF-200A, single axis, $60.00) and proved
it. I was getting over 199 mg at the wall about 2" from the conduit
behind sheetrock. It went off the scale about an inch from the wall."
 
Rich Grise wrote:
On Thu, 17 Mar 2005 12:21:45 -0700, Bryan wrote:


Hello one and all.

I have been looking into building a "very" sensitive EMF detector due to
issues with power lines in the area. I am sorry to say that I have no REAL
idea on how to do it.
I was also told that there is a way to build a device that would use Hall
effect sensors to measure the earths magnetic field. It would be much more
sensitive and would work if adjustable. I have yet to find a circuit design
that will give a visual as well as audible measurement. An LED bar graph
would be ok.
Any good ideas on what I could build that would do this?

Thanks for your help.



I'd say that if they're too low to detect except with specialized ultra-
high sensitivity equipment, you're blowing smoke up your own ass.

Cheers!
Rich
Click to expand...
Try Google: +"smoke detector" +anal

--
Luhan Monat (luhanis 'at' yahoo 'dot' com)
"The future is not what it used to be..."
http://members.cox.net/berniekm
 
to start, think about this

do you want to measure the ELECTRIC field at 60 Hz?

or

do you want to measure the MAGNETIC field at 60 Hz?

that is two completly different measurments.

Measuring an electomagnetic field implies you are in the far field
meaning you are many wavelengths away from the source which at 60 Hz is
several miles.

Mark
 
I read in sci.electronics.design that Mark <makolber@yahoo.com> wrote
(in <1111109333.304096.190240@f14g2000cwb.googlegroups.com>) about 'EMF
Detector made easy?', on Thu, 17 Mar 2005:
to start, think about this

do you want to measure the ELECTRIC field at 60 Hz?

or

do you want to measure the MAGNETIC field at 60 Hz?

that is two completly different measurments.
Click to expand...
Absolutely. The OP clearly understands so little about the subject that
advice on making a detector is futile.
Measuring an electomagnetic field implies you are in the far field
meaning you are many wavelengths away from the source which at 60 Hz is
several miles.
Click to expand...
For 55 Hz, the distance is approximately 1000 km.
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
"Bryan" <abel6479@cox.net> wrote in message
news:eNk_d.14802$Fy.5619@okepread04...


Any good ideas on what I could build that would do this?
Click to expand...
A Proton Magnetometer for entertainment/nerd value or a Flux-Gate can
measure the magnetic field component - *what for* and *how to calibrate* is
for the user.

Maybe easiest to buy?

The Electric component can be seen in the dark when holding a flourescent
tube at one end and the other closer to the wires - The 440 kV "SuperGrid"
crossing Didcot, UK will light up the tube a fair bit.

I did the experiment after getting small chocks while carrying a
well-insulated child in a Nylon suit on my shoulders below the wires
whenever child touched my head.

Anyway - Electrometer is the word, I think.
 
Watson A.Name - "Watt Sun, the Dark Remover" wrote:
"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.03.18.16.02.04.271952@example.net...

On Thu, 17 Mar 2005 12:21:45 -0700, Bryan wrote:


Hello one and all.

I have been looking into building a "very" sensitive EMF detector

due to

issues with power lines in the area. I am sorry to say that I have

no REAL

idea on how to do it.

You could check with some of the strawberry growers who are using the
whole corridor under the hi-line alongside I-605. They might know
something about the effects of power line induction.

Good Luck!
Rich


GASP! You mean those strawberries we eat have been irradiated?!? Don't
let the organic nuts know!

People don't realize how much of an electrostatic field there is around
those high tension lines. But it rapidly dissipates after a few scores
of feet.
Click to expand...
My girlfriend and I were once driving down a road with lots of
high-tension lines above..(Going down LoLo Pass,on Mt.Hood,in Oregon,the
wires were coming from the Bonneville dam.)
And with the sun-roof open we could hear them hissing and buzzing..
We noticed after a while we felt kind of "odd"..not really dizzy
but,"wierd-headed"..
We both noticed it,and I commented to her about it,and she had noticed
it about the same time..
The lines are pretty dang low in some places,I probably could have stood
out of the sunroof,and raised my arm,and got an arc to jump to
me,they're only like 15-20 feet overhead in places!!
Wierd stuff.
 
"ptaylor" <ptaylor@nospam.qwest.net> wrote in message
news:Bkc%d.1$tc1.319@news.uswest.net...
Watson A.Name - "Watt Sun, the Dark Remover" wrote:
"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.03.18.16.02.04.271952@example.net...

On Thu, 17 Mar 2005 12:21:45 -0700, Bryan wrote:


Hello one and all.

I have been looking into building a "very" sensitive EMF detector
due to
issues with power lines in the area. I am sorry to say that I have
no REAL
idea on how to do it.

You could check with some of the strawberry growers who are using
the
whole corridor under the hi-line alongside I-605. They might know
something about the effects of power line induction.

Good Luck!
Rich

GASP! You mean those strawberries we eat have been irradiated?!?
Don't
let the organic nuts know!

People don't realize how much of an electrostatic field there is
around
those high tension lines. But it rapidly dissipates after a few
scores
of feet.


My girlfriend and I were once driving down a road with lots of
high-tension lines above..(Going down LoLo Pass,on Mt.Hood,in
Oregon,the
wires were coming from the Bonneville dam.)
And with the sun-roof open we could hear them hissing and buzzing..
We noticed after a while we felt kind of "odd"..not really dizzy
but,"wierd-headed"..
We both noticed it,and I commented to her about it,and she had noticed
it about the same time..
The lines are pretty dang low in some places,I probably could have
stood
out of the sunroof,and raised my arm,and got an arc to jump to
me,they're only like 15-20 feet overhead in places!!
Wierd stuff.
Click to expand...
You were probably deceived by the lack of something to compare them to,
and they were much higher than 20 feet. There is something like 800
feet between towers, and the lines can sag somewhat, but they have to be
certain heights above ground because of the high voltages, which can be
a half million volts. The humdity in the air makes the crackling
louder, but there's always some corona discharge when the voltages are
that high.

Check this out. Click on BIG Arcs and Sparks and D/L one and view it.
http://www.teslamania.com/
 
why do you think it was the HT lines?

maybe you should check your car for CO

Mark
 
Watson A.Name - "Watt Sun, the Dark Remover" wrote:
"ptaylor" <ptaylor@nospam.qwest.net> wrote in message
news:Bkc%d.1$tc1.319@news.uswest.net...

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.03.18.16.02.04.271952@example.net...


On Thu, 17 Mar 2005 12:21:45 -0700, Bryan wrote:



Hello one and all.

I have been looking into building a "very" sensitive EMF detector

due to

issues with power lines in the area. I am sorry to say that I have

no REAL

idea on how to do it.


You could check with some of the strawberry growers who are using

the

whole corridor under the hi-line alongside I-605. They might know
something about the effects of power line induction.

Good Luck!
Rich

GASP! You mean those strawberries we eat have been irradiated?!?

Don't

let the organic nuts know!

People don't realize how much of an electrostatic field there is

around

those high tension lines. But it rapidly dissipates after a few

scores

of feet.


My girlfriend and I were once driving down a road with lots of
high-tension lines above..(Going down LoLo Pass,on Mt.Hood,in

Oregon,the

wires were coming from the Bonneville dam.)
And with the sun-roof open we could hear them hissing and buzzing..
We noticed after a while we felt kind of "odd"..not really dizzy
but,"wierd-headed"..
We both noticed it,and I commented to her about it,and she had noticed
it about the same time..
The lines are pretty dang low in some places,I probably could have

stood

out of the sunroof,and raised my arm,and got an arc to jump to
me,they're only like 15-20 feet overhead in places!!
Wierd stuff.


You were probably deceived by the lack of something to compare them to,
and they were much higher than 20 feet.
Click to expand...
Yea,they probably were higher than 20 feet,but MAN they look LOW..
It's funny when you see the wires up close,and realise that the "little"
cables up there are like 4 inches diameter! (and there's 3 cables per
conductor/phase,connected together with Y shaped pieces.) and those long
glass insulators they're hanging from..they must be like 10 feet long!

The crackling/hissing/buzzing noises are kinda freaky.
I should go up there and take pics,or video or something..
It's a creepy place! Desolate gravel "pits" on the side of the
road,where people shoot off guns,and dump rubbish..


There is something like 800
feet between towers, and the lines can sag somewhat, but they have to be
certain heights above ground because of the high voltages, which can be
a half million volts. The humdity in the air makes the crackling
louder, but there's always some corona discharge when the voltages are
that high.

Check this out. Click on BIG Arcs and Sparks and D/L one and view it.
http://www.teslamania.com/
Click to expand...
 
I read in sci.electronics.design that Watson A.Name - "Watt Sun, the
Dark Remover" <NOSPAM@dslextreme.com> wrote (in <113qmd42g0cb9df@corp.su
pernews.com>) about 'EMF Detector made easy?', on Sun, 20 Mar 2005:
You were probably deceived by the lack of something to compare them to,
and they were much higher than 20 feet.
Click to expand...
How close do you get to the overhead cables at the train station? Very
close, in UK (3 m minimum, I believe) and they have 25 kV 50 Hz on them.
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
"ptaylor" <ptaylor@nospam.qwest.net> wrote in message
news:Kxu%d.53$tc1.1224@news.uswest.net...
Watson A.Name - "Watt Sun, the Dark Remover" wrote:
"ptaylor" <ptaylor@nospam.qwest.net> wrote in message
news:Bkc%d.1$tc1.319@news.uswest.net...

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.03.18.16.02.04.271952@example.net...

On Thu, 17 Mar 2005 12:21:45 -0700, Bryan wrote:

Hello one and all.
I have been looking into building a "very" sensitive EMF detector
due to
issues with power lines in the area. I am sorry to say that I
have
no REAL idea on how to do it.
You could check with some of the strawberry growers who are using
the
whole corridor under the hi-line alongside I-605. They might know
something about the effects of power line induction.

Good Luck!
Rich

GASP! You mean those strawberries we eat have been irradiated?!?
Don't let the organic nuts know!
People don't realize how much of an electrostatic field there is
around
those high tension lines. But it rapidly dissipates after a few
scores of feet.

My girlfriend and I were once driving down a road with lots of
high-tension lines above..(Going down LoLo Pass,on Mt.Hood,in
Oregon,the wires were coming from the Bonneville dam.)
And with the sun-roof open we could hear them hissing and buzzing..
We noticed after a while we felt kind of "odd"..not really dizzy
but,"wierd-headed"..
We both noticed it,and I commented to her about it,and she had
noticed
it about the same time..
The lines are pretty dang low in some places,I probably could have
stood
out of the sunroof,and raised my arm,and got an arc to jump to
me,they're only like 15-20 feet overhead in places!!
Wierd stuff.

You were probably deceived by the lack of something to compare them
to,
and they were much higher than 20 feet.

Yea,they probably were higher than 20 feet,but MAN they look LOW..
It's funny when you see the wires up close,and realise that the
"little"
cables up there are like 4 inches diameter! (and there's 3 cables per
conductor/phase,connected together with Y shaped pieces.)
Click to expand...
The high tension lines that terminate here locally in a huge switchyard
come across the desert and mountains from Hoover dam and Lake Mead.
They were adding more conductors and the new ones were laying on the
ground, so I went over to the fence to check them out. They were about
1.3" (33mm)in diameter, and must weigh several pounds per foot. There
are six aluminum strands around a center steel strength member. Each
insulator holds two conductors. I think the insulator is longer than 6
feet. But they say that the closer the lines are to the ocean, the more
insulators they add, because of the salt in the air.

and those long
glass insulators they're hanging from..they must be like 10 feet long!

The crackling/hissing/buzzing noises are kinda freaky.
I should go up there and take pics,or video or something..
It's a creepy place! Desolate gravel "pits" on the side of the
road,where people shoot off guns,and dump rubbish..


There is something like 800
feet between towers, and the lines can sag somewhat, but they have
to be
certain heights above ground because of the high voltages, which can
be
a half million volts. The humdity in the air makes the crackling
louder, but there's always some corona discharge when the voltages
are
that high.

Check this out. Click on BIG Arcs and Sparks and D/L one and view
it.
http://www.teslamania.com/
Click to expand...
 
On Mon, 21 Mar 2005 23:45:23 -0800, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:

The high tension lines that terminate here locally in a huge switchyard
come across the desert and mountains from Hoover dam and Lake Mead.
Click to expand...
That's a fine piece of writing. Sounds like the first sentence of a good
novel.

Interesting technical information followed too.
 
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