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Question about EM Spectrum, and EM Fields


jjrakman

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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?

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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 :)

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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.

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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.

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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.?

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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:

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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

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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!

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  • 2 weeks later...
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?

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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.

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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".

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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:

 

377px-Electromagnetic-Spectrum.png

 

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?

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