If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #2385
Joined: Thu Sept 24 2009, 01:26AM
Location: Waxhaw, North Carolina (Or Charlotte near UNCC)
Posts: 26
I was wondering if anyone had built an EMF detector. It would be cool to have and I would like to make one instead of buying one. That is, of course, if it's cheaper. Didn't know if there was some kind of complex circuitry at all.
Registered Member #1623
Joined: Tue Aug 05 2008, 03:31PM
Location: The Netherlands
Posts: 39
Measuring EMF is very difficult, first you would need a faraday cage because else it will be impossible to seperate the noise from the signal. Then you would need an antenna that is built for the frequency range you would like to measure and connect that to at least a spectrum analyser. There is specialized equipment for this only I don't know the english terms for these devices. But it is very hard to get an accurate measurement, the theoretical maximum accuracy (at the moment) is +- 4,8dB and that is with state of the art equipment. And this is just for measuring the field at 1 point so you only know the field at a given distance from the source. I don't know why or what you want to measure exactly but measurement of EMF is very hard.
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
If you mean a meter for detecting direct current magnetic fields, such as terrestrial magnetism, we would call such an instrument a gauss meter, or magnetometer. A compass needle is the simplest possible type of magnetometer.
A very basic instrument for detecting alternating magnetic fields, such as the field around power pylons, or around a television, need not be hard to make on a small budget.
If you'd just like to tell us a bit more about what you hope to do with your EMF detector, it will be easier to come up with a more definite answer.
Registered Member #2261
Joined: Mon Aug 03 2009, 01:19AM
Location: London, UK
Posts: 581
My understanding is that "EMF" (Electromotive Force) is just an old term for voltage so to me you appear to be asking "How do I measure voltage". Presumably you don't mean this, so can you say a bit more about what you want to measure?
Registered Member #2463
Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546
EMF E,M.F. ( ELEC, ENG.) a commonly used abbrev. for electromotive force. The force which causes electricity to move around a circuit--from CHAMBERS'S technical dictionary , 3rd ed. 1940. (with supplement 1958.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
EMF
