Subject: Re EMF-L Measurement Protocols Date: Thu, 24 Jul 1997 084133 -0500 (CDT) From: kriley3@ix.netcom.com To: Multiple recipients of list <emf-l@mail.llion.org> -------------------------------------------------- Andrea: You will find power frequency measurement protocols in my book, Tracing EMFs in Building Wiring and Grounding, the contents of which I faxed to you last night. But protocols vary depending on what the purpose of the study is. Epidemiologists have at times taken only one measurement per house. I take measurements throughout the building in a grid of about every six feet, with a three-axis gaussmeter. But my purpose is to locate sources for mitigation. I switch to single axis for locating sources and also to tell if the field from a power line is balanced or if there is net current on the line. The Dr. Gauss meter, which measures up to 10 mG, is probably the best of the cheapies, but it has a linear response to frequency, which means it does not read harmonic frequencies correctly. It will read a 4 mG field produced by the third harmonic as 12 mG. Best to use a meter with a flat frequency response over the frequency band of interest. Karl Riley Archive provided courtesy of WaveGuide, http://www.wave-guide.org Reprinted with permission of Roy Beavers, http://www.feb.se/EMF-L/EMF-L.html