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Bill D.
USA
46 Posts |
 Posted - 08/20/2019 : 16:07:58
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My attempt to detect lightning EF was not very successful. Readings were taken outside. As the storm rolled in the meter did not change by more than a couple of V/m. However, the magnetic field did change by a few Gauss with each nearby lightning strike. According to Alpha Labs the electric field will fluctuate indoors by as much as 100 V/m during a storm using their TriField Natural EM Meter (https://www.trifield.com/wp-content/uploads/2017/05/NEM-2015.pdf). The GQ-390 has a slightly better sensitivity according to the specs, so I was surprised to see so little fluctuation.
Any suggestions on how to improve lightning EF detection? Or, is detection in this case limited by the type of sensor? |
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| Reply #1
EmfDev
2250 Posts |
Posted - 08/21/2019 : 09:30:36
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| Bill D, I don't know maybe do more testing? is how far are the lightnings? |
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| Reply #2
Bill D.
USA
46 Posts |
Posted - 08/21/2019 : 10:46:26
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| The strokes were close, but not overhead. I will try some different configurations (e.g., placing the detector on a grounded metal plate). More testing! |
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| Reply #3
EmfDev
2250 Posts |
Posted - 08/21/2019 : 11:33:01
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| Does the lightning affect the EF of the ground and the whole house? try holding it during the lightning so you can act as an antenna. Don't know if that works. |
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| Reply #4
Bill D.
USA
46 Posts |
Posted - 08/21/2019 : 15:18:57
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| I will try it both ways. The charge from the clouds induces a ground charge. So the air between is like the space between the plates of a capacitor (in fact, there is even a slight charge under a clear sky of several millivolts based on other equipment I have built). I would expect much less of an effect indoors. |
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| Reply #5
Bill D.
USA
46 Posts |
Posted - 09/11/2019 : 16:07:37
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| Discovered today that for lightning detection you have to monitor the peak EF, not the current EF. Most flashes don't show up on the current EF display, but the stronger ones are recorded as peak values. From where I was standing, peak values were in the 40s and 50s V/m. I believe the same is true of EMF. |
Edited by - Bill D. on 09/11/2019 16:12:09 |
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| Reply #6
EmfDev
2250 Posts |
Posted - 09/12/2019 : 10:51:36
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| It should have been in the graph if you didn't catch it. Are you sure that's from the lightning? and not from random EF around? |
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| Reply #7
Bill D.
USA
46 Posts |
Posted - 09/12/2019 : 15:04:31
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| Just to clarify, it does show up on the graph as well, but not on the real time numerical display. I am pretty sure it's lightning, but I need to do more testing to be sure. |
Edited by - Bill D. on 09/12/2019 16:38:48 |
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| Reply #8
EmfDev
2250 Posts |
Posted - 09/12/2019 : 15:23:30
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| If the lightning is close enough, it sure to be detected. |
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Topic |
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Lightning Detection
