Electromagnetic fields: what thresholds for health?

[Diablo]

Hello,

I introduce myself, Lionel 41 years old living in the Paris region, I bought on the site a electromagnetic field detector with a view to purchasing a building plot in Eure et Loir along a 20 kV MV line.

I ask myself questions of the kind, I understand that France authorized an exposure to 500 mtesla for a worker, 100 for an individual, and some countries to 0.2 mt ...

Which makes quite deviations, unless I didn't understand.

Tonight I went under a 20 kv line and my detector gave only 0.1 mt, my radiant floor 0.1 mt and my radiant convector, nothing either ...

However, by reading here and there, I read much more important measures with high safety distances ...

Do you think that the detector is "reliable" knowing that it is not a measuring device, but a detector and if it is not, can one count on "at worst" a measurement of half of the real value?

Well, I am not very clear perhaps, finally, thank you in advance for your opinions.

[Christophe]

Are you speaking in micro (µT) or mT (milliT)?
500 µT is already huge and well beyond the sanitary threshold ... so 500 milli (1000 times more ...) I don't talk about it!

The detector is reliable, it measures this range:

- Indication by LEDs: 1, 3, 6 and 10mG (i.e. 0.1, 0.3, 0.6 and 1 µT).

This starts to be "dangerous" in the long term from 0.5 µT but it obviously depends on the frequency of the signal.

To better understand all this, I advise you to read this document carefully: https://www.econologie.com/forums/ondes-elec ... 10188.html (in link on the product sheet: https://www.econologie.com/shop/detecteu ... p-143.html )

Watch this video if not already done: http://www.dailymotion.com/video/x5ogic ... maiso_tech

[Diablo]

Good evening Christophe,

I'm talking about a microphone, I hadn't seen that I had the symbol on the keyboard ...

We are going to say for the frequency, that of the HV lines to start or the home network, all that must be 50 Hz?

PS: I went through a few subjects of the forum and I don't have the technical knowledge of some ...

Thanks for the link, I'll read it.

[Christophe]

In 50/60 Hz it is around 0.5 µT the danger threshold ...

If you have read 500 µT it is possible but it is that France has a hell of a delay ... like elsewhere for the thresholds in microwave ...

[Diablo]

Ok, and you see, on a doc. found on the net, they measure under a line 20 kv, 6 µt and I 0 / 0.1 ... maybe it was not 20 kv, two insulators.

I went to work with the device on in the car and passed under THT lines, really big ones, well it only sounded very close and under, obviously, but it is indicated in many places distances security up to 1000 m distance.

I have difficulties to understand...

And in the linked booklet, a heated floor gives 2.6 µT at 25 cm and I measure 0.1 to 1 cm ...

I don't get the same measurements ...

So who should we be proud of?

[bamboo]

I went to work with the device on in the car and passed under THT lines, really big ones, well it only sounded very close and under, obviously, but it is indicated in many places distances security up to 1000 m distance.

The car isolates you from the fields ...
If you want to make more reliable measurements, take your device and walk ...

[Christophe]

So who should we be proud of?

The intensity of the field depends on the power which passes in the conductor which one measures ... Also it is necessary that the field of your floor is alternating (if not must move the sensor).

Have you watched the little video I posted above? We can see it with the switch in my garage ...

[dedeleco]

In 50/60 Hz it is around 0.5 µT the danger threshold.

Very low value often exceeded at home and elsewhere.
Do you have an idea of ​​the Earth's magnetic field in µT ???
Do you have an idea of ​​the magnetic field near a conductor with 1A or 10A in it (220W or 2,2kW) ???
Do you have an idea of ​​the magnetic fields pulsed in a magnetic resonance medical examination (on the proton nuclei of your body) ???
Do you have an idea of ​​the magnetic field detected by a dowser who finds a source ???? (a real scientific mystery)?
There is all the scientific contradiction !!!
Look for some of my posts on econology or read wikipedia or google !!

The magnetic field is less of a problem than the voltages induced at a much higher frequency in Volts / m, in particular microwave waves for mobile phones!

The car isolates you from the fields ...

is an anti-scientific phrase because too vague, like mixing microTesla, milliTesla and V / m !!

The electric fields are strongly screened to the point of protecting from lightning !!
But not the magnetic fields until the walls of the car are not thick enough. They can even be increased, if unlucky as in the gap of a transformer !!!

I invite you to understand the scientific properties, and also the units, because on the subject we see too many absurd salads !!!

[bamboo]

The car isolates you from the fields ...

is an anti-scientific phrase because too vague, like mixing microTesla, milliTesla and V / m !!

The electric fields are strongly screened to the point of protecting from lightning !!
But not the magnetic fields until the walls of the car are not thick enough.

The measurement remains disturbed in a car.
See your example of the transformer.

They can even be increased, if bad luck as in the gap of a transformer !!!

In a transformer the magnetic circuit is used to transport energy from one point of the transformer (the primary) to another (the secondary).
To return to the car: the car takes (partly!) The magnetic field picked up by the roof towards the floor of the car.
The internal measurement is therefore inaccurate!

Otherwise :
- the car itself produces internal magnetic fields, which also disturb the measurement!
- for the transformer: the magnetic fields of the air gap come rather from the turns which, to be able to go around the magnetic circuit, pass (also) through the air gap!

[dedeleco]

With this sentence:

the magnetic fields of the air gap rather come from the turns which, to be able to go around the magnetic circuit, pass (also) through the air gap!

the turns wander in the magnetic circuit by going around it !!!! (sic, to put in the Humor section) !!!
Question: why the field (induction in reality) prefers the magnetic circuit ???
I ask the questions now instead of putting wikipedia or google !!!
For the order of magnitude of the magnetic field, the car does not fundamentally change, (either changed by a factor of 10) except to put the device against or in a very large metallic mass, as in the engine !!
In these measurements we look at a factor of 10, given the possible variations !!