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n8xyn
USA
66 Posts |
 Posted - 01/01/2019 : 12:54:44
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| EMF in my understanding is a fluctuating magnetic field and my home is acceptable as for as that goes but EF is high what does EF reflect? |
Jim Whitaker |
Edited by - n8xyn on 01/01/2019 12:55:46
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| Reply #1
EmfDev
2250 Posts |
Posted - 01/14/2019 : 15:09:36
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| Electric fields mostly from power lines. |
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| Reply #2
Bill D.
USA
46 Posts |
Posted - 08/13/2019 : 15:28:52
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| Household current is 120V, yet I pick up EF readings up to 1500 V/m near outlets and breaker boxes. How is that possible? |
Edited by - Bill D. on 08/13/2019 15:29:57 |
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| Reply #3
EmfDev
2250 Posts |
Posted - 08/13/2019 : 15:48:50
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| Those two are different things. 120V is the voltage of the outlet and has reference to its ground that can provide current for devices. Electric field is the field around charges that can cause force to there charges. |
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| Reply #4
Bill D.
USA
46 Posts |
Posted - 08/13/2019 : 19:38:34
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| Yes, I see the difference. But it's hard to comprehend how such high voltages are generated in the field. Is it like a feedback loop?: Current creates an oscillating magnetic field, this field creates current which in turn creates a magnetic field, etc. |
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| Reply #5
EmfDev
2250 Posts |
Posted - 08/14/2019 : 09:56:24
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| Could be. It could also be from static around it. Those two are different things. Like you can generate few thousand EF from the carpet. It doesn't even have voltage. |
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| Reply #6
Bill D.
USA
46 Posts |
Posted - 08/14/2019 : 12:44:12
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In searching for an answer I came across what is called the near-field effect of antennas (since a power line is a low freq antenna): "Very close to the antenna, in the reactive region, energy of a certain amount, if not absorbed by a receiver, is held back and is stored very near the antenna surface. This energy is carried back and forth from the antenna to the reactive near field by electromagnetic radiation of the type that slowly changes electrostatic and magnetostatic effects..." Wikipedia https://en.wikipedia.org/wiki/Near_and_far_field
There are diagrams showing these regions.
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| Reply #7
EmfDev
2250 Posts |
Posted - 08/14/2019 : 13:07:25
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| Could be, but these are for antennas. |
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| Reply #8
Bill D.
USA
46 Posts |
Posted - 08/14/2019 : 19:37:19
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| Finally, near some outlets and breaker boxes I get readings approaching 2000 V/m. But the specs indicate that the 390 has a range of only 0-1000 V/m. Apparently the scale extends beyond 1000 V/m or does it lose accuracy past that point? |
Edited by - Bill D. on 08/15/2019 05:30:30 |
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| Reply #9
EmfDev
2250 Posts |
Posted - 08/15/2019 : 09:04:55
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| It's a little less accurate above 1000 range. |
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Quickly explain EF
