jjrakman Posted July 12, 2007 Share Posted July 12, 2007 I'm attempting to understand their difference, and their relationship. The Electomagnetic Specturm ranges from Gamma Waves to Long Wave Radio waves, and everything in between. Electromagnets and other kinds of electronic equipment and power lines give off electromagentic fields. My question is, are the electromagnetic fields emanating from electronic equipment and other electromagnetic sources, part of the Electromagnetic Specturm? If so, what portion are they in? If not, what is their relationship? Link to comment Share on other sites More sharing options...
swansont Posted July 12, 2007 Share Posted July 12, 2007 It depends on their frequency. A device running at 60 Hz will be giving off radiation at 60 Hz. You need look at the frequency or wavelength scale on the spectrum. Link to comment Share on other sites More sharing options...
YT2095 Posted July 12, 2007 Share Posted July 12, 2007 whenever a changing current passes through a conductor you can be certain that it is in the EM spectrum. so yes, every electronic piece of kit that you have and use (even battery powered including your watch) is giving off signals Link to comment Share on other sites More sharing options...
jjrakman Posted July 13, 2007 Author Share Posted July 13, 2007 whenever a changing current passes through a conductor you can be certain that it is in the EM spectrum. So what portion(s) of the electromagentic spectrum do these electromagnetic fields lie in? Link to comment Share on other sites More sharing options...
insane_alien Posted July 13, 2007 Share Posted July 13, 2007 depends on the frequency of the current. generally at the longer wavelength side. Link to comment Share on other sites More sharing options...
jjrakman Posted July 13, 2007 Author Share Posted July 13, 2007 So if I'm using an EMF meter to look for electromagnetic fields around my house, what portion of the electromagnetic field am I looking at? I guess I'm having a hard time understanding the distinction between what is laid out in the electromagnetic spectrum, and what is given off in electromagnetic fields. Link to comment Share on other sites More sharing options...
YT2095 Posted July 13, 2007 Share Posted July 13, 2007 any CHANGING electrical current in a conductor will give off EM radiation. this change can be at Any rate even once a second. the things around you home are likely to main Line frequency 50 or 60 Hz depending on your country, things like the 16KHz flyback transformer in your TV set, electric motors (frequency depends on spin rate and windings connected to the comutator) if you have Compact fluorescent bulbs then you`ll be getting 6 to 7 KHz broadband multi-phasic sweep etc.... there`s plenty of things that make EM noise in and around the home. Link to comment Share on other sites More sharing options...
jjrakman Posted July 14, 2007 Author Share Posted July 14, 2007 Sorry to be so difficult, just trying to understand here. the things around you home are likely to main Line frequency 50 or 60 Hz depending on your country, things like the 16KHz flyback transformer in your TV set, electric motors (frequency depends on spin rate and windings connected to the comutator) if you have Compact fluorescent bulbs then you`ll be getting 6 to 7 KHz broadband multi-phasic sweep etc.... So what portion of the electromagnetic spectrum is that, is that radio waves, infrared, gamma waves, etc.? Link to comment Share on other sites More sharing options...
pulasthi Posted July 14, 2007 Share Posted July 14, 2007 friends, When ever there is an event associated with high energy electrons, there is a photon emission, so there is an electromagnetic radiation generated. Energy of the photons has something close to a normal distribution thus they form a spectrum. That's as simple as that. check out my site: http://www.pulasthi.info thanks Sorry to be so difficult, just trying to understand here. So what portion of the electromagnetic spectrum is that, is that radio waves, infrared, gamma waves, etc.? friend, most this at your work place or at home emmits eletromagnetic radiation in the form of heat, thus infrared waves. check out my site: http://www.pulasthi.info Hope you understand now:eyebrow: Link to comment Share on other sites More sharing options...
Klaynos Posted July 14, 2007 Share Posted July 14, 2007 Accelerating charges radiate.... Important statement that... Sorry to be so difficult, just trying to understand here. So what portion of the electromagnetic spectrum is that, is that radio waves, infrared, gamma waves, etc.? The spectrum is just a list of frequencies/wavelengths, people have named bits of it. If you look here: http://www.astro.virginia.edu/class/skrutskie/images/light_em_spectrum.jpg You can see the wavelengths listed wavelength = speed of light / frequency Link to comment Share on other sites More sharing options...
YT2095 Posted July 14, 2007 Share Posted July 14, 2007 most this at your work place or at home emmits eletromagnetic radiation in the form of heat, thus infrared waves. that`s utterly Useless to the OP, what he picking up is EM radiation in the Radio section for the most part (and that extends down to but not including 0Hz). with an EMF meter most Definitely he will be "seeing" the Radio part. IR is NOT detectable with an EMF meter I can assure! Link to comment Share on other sites More sharing options...
jjrakman Posted July 25, 2007 Author Share Posted July 25, 2007 that`s utterly Useless to the OP, what he picking up is EM radiation in the Radio section for the most part (and that extends down to but not including 0Hz).with an EMF meter most Definitely he will be "seeing" the Radio part. IR is NOT detectable with an EMF meter I can assure! O.k. So electromagetic fields coming off of electronics and wiring, is only a certain portion of the electromagnetic spectrum? So which portion is it? Link to comment Share on other sites More sharing options...
swansont Posted July 26, 2007 Share Posted July 26, 2007 O.k. So electromagetic fields coming off of electronics and wiring, is only a certain portion of the electromagnetic spectrum? So which portion is it? It will depend on the frequency. If the oscillation is RF, you will be in the RF part of the spectrum. If the oscillation is ELF, then they will be in the ELF part of the spectrum. Link to comment Share on other sites More sharing options...
jjrakman Posted July 27, 2007 Author Share Posted July 27, 2007 So looking at this graph: Where is the RF and ELF portion of the spectrum located? Link to comment Share on other sites More sharing options...
YT2095 Posted July 27, 2007 Share Posted July 27, 2007 see the line between Radar and Infra red? well anything Right of that line is Radio, ELF isn`t shown nor ULF but it`s below the AM section even or at least the lowest part of the AM section. I will point out that although you picture is ok for showing the Visible, it`s not strictly accurate in it naming, AM and FM are not "Bands" they are Modes of transmission and Radar is an Application not a band either, Microwave would be better in place of Radar, UHF and VHF and some HF is better than saying "FM" or "TV", Medium wave and Longwave is better than saying "AM". Link to comment Share on other sites More sharing options...
swansont Posted July 27, 2007 Share Posted July 27, 2007 http://en.wikipedia.org/wiki/Electromagnetic_spectrum has a more detailed breakdown, but note that the divisions are somewhat arbitrary. Different sources will have slightly different labels and cutoffs. Link to comment Share on other sites More sharing options...
YT2095 Posted July 27, 2007 Share Posted July 27, 2007 yeah, that`s a Much better chart(s) and to complete it a little more: http://en.wikipedia.org/wiki/Ultra_low_frequency and that (as far as I know) is as deep as the rabbit hole goes! (without going into cosmological periodicity) Link to comment Share on other sites More sharing options...
jjrakman Posted July 28, 2007 Author Share Posted July 28, 2007 O.K., so if I were looking at this graph: What portions would I color in to represent the EMF given off by electrical gear that can be detected by an EMF Meter? Link to comment Share on other sites More sharing options...
Klaynos Posted July 28, 2007 Share Posted July 28, 2007 Well mains is ~50Hz so off the bottom... Link to comment Share on other sites More sharing options...
jjrakman Posted July 28, 2007 Author Share Posted July 28, 2007 Well mains is ~50Hz so off the bottom... Mains, do you mean a main electrical line? And do you mean 50MHz? Just below VHF in the Radio section? Link to comment Share on other sites More sharing options...
Klaynos Posted July 28, 2007 Share Posted July 28, 2007 Yes, main electrical line, mains power is what you get from your wall sockets in most countries it's between 40 and 60Hz, and no I really do mean Hz not MHz. Link to comment Share on other sites More sharing options...
jjrakman Posted July 28, 2007 Author Share Posted July 28, 2007 Sorry for being a dolt, I'm trying to wrap my head around these concepts in a Physics for Dummies kind of way. But I'm having a hard time finding 50Hz on this graph: You say it's off the bottom, below Long-Waves? By off the bottom, do you mean to say that it's not represented on the chart? Link to comment Share on other sites More sharing options...
Klaynos Posted July 28, 2007 Share Posted July 28, 2007 Yeah not represented on there... Link to comment Share on other sites More sharing options...
jjrakman Posted July 28, 2007 Author Share Posted July 28, 2007 So if that kind of EMF is not represented in that graph, would there be another graph that does represent it? Link to comment Share on other sites More sharing options...
Klaynos Posted July 28, 2007 Share Posted July 28, 2007 I looked for one but they all seem to stop at around the 1km wavelength point. Link to comment Share on other sites More sharing options...
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