Why Does My Wireless Current Flow Detector Indicate Voltage Throughout the Wall?

Hello!

I don`t know if this is the right forum for my question, if not, please move it.
Well, I have a wireless current flow detector. Just today I placed it against the wall and it detected the flow of current (it lit up) over almost the entire wall. There is an electricity meter on this wall, although I don`t think it`s his fault because I checked it about 2 m from the meter and in places where I`m sure there are no wires running through it. The sensor is definitely working. And with this sensor it`s hard to detect the flow of current in the wire. already 2 cm and there is only brick in the wall and it detects it.
What could it be? I`m asking for help because I`m very curious about this and I`m asking for a rational solution to this phenomenon. Best regards and thank you in advance for all your help

Try again, but do not touch the sensor directly to the wall.

Your "meter" does not detect current flow, only radio waves caused by the presence of voltage. If there is reinforcement in the wall, pipes parallel to the cables, if the wall is damp, etc., the meter will signal by induction.
That`s it, you`re welcome

cranky wrote:

Your "meter" does not detect current flow, only radio waves caused by the presence of voltage. If there is reinforcement in the wall, pipes parallel to the cables, if the wall is damp, etc., the meter will signal by induction.
That`s it, you`re welcome

The instructions for this meter/sensor probably said not to use it in Krakow due to RMF FM. Your wall emits these radio waves because it is connected to the hamster`s urethra and your neighbor`s water vapor condenser, and therefore it has turned into a giant antenna broadcasting The Very Best of Cher.

Sorry, I couldn`t resist.

It would be best if you wrote what the sensor is, it would be easier, mainly the principle of operation.
Here is a quote from the manual for such a device
"Voltage detection is carried out in the same way as in the case of metal detection.
- some walls may contain metal wires which may extend the voltage identification area,
- rubbing or hitting the device may cause incorrect readings to be generated,
- a small amount of electricity may cause the device to start up and cause incorrect detection,
- when a reading about no voltage appears, check the instrument at a source known to the user
voltage before touching any wire,
- the detector does not detect the voltage of shielded cables, it will only indicate the presence of metal,
- if you are unsure about the measurement, do not take the risk but consult a qualified professional
electrician.
5.4."

hello and thanks for your help. It`s probably the fault of some reinforcement, but I won`t tear down the wall to find out.

And this is the detector I have.
http://www.maplin.co.uk/Module.aspx?ModuleNo=45560#features

I didn`t hit anything with the meter and I tested it several times and it was always the same. The sensor reacts at a distance of about 2 cm from the wall.

mąci wrote:

Well, I have a wireless current flow detector.

This is not any "current flow detector". This is just a voltage detector (alternating electric field detection). Current detectors, in turn, operate on a magnetic field.

I have several of them at home, each of them reacts slightly differently. One, which is built into the FC-33 clamp (cem), even reacts to the approach and separation of charged insulators.

best regards
-DAREK-

I`m sorry if I offended users.

When we cause a change in the electric potential in a part of a conductor, we cause a change in the magnetic field, the change of which causes a change in the electric field and we obtain an electromagnetic wave with a length depending on the frequency. It does not matter whether the conductor is a piece of wire "out in the open", a piece of ungrounded reinforcement in concrete, or even a wet (though poor conductor) piece of concrete.
The resulting electromagnetic wave has different names depending on its length/frequency. According to Wikipedia, radio waves are those with wavelengths above 1exp-4 meters. Electromagnetic waves with a frequency of 50 Hz have enormous lengths, so they can be called radio waves and not just an electromagnetic wave.
As a result of induction, a variable potential difference will be induced in any part of the conductor, especially those parallel to the wires. It will be a source of secondary - "false" radiation, although with a much lower amplitude ("strength") than the real transmitter. However, since the "secondary" source is located at a much shorter distance from the "meter", it will be detected as a stronger signal. Pipes, reinforcement and concrete do not block radio waves under certain conditions (mainly lack of grounding), but are only a secondary source of them.
Because the phaser sensor is actually a receiver tuned to 50Hz, it will detect every element radiating at this frequency (or harmonic).
An interesting use of this phenomenon are "magic" cell power and range amplifiers. These are fragments of a conductor with an appropriately selected shape that change the way the waves are radiated by the phone. Usually, if they improve the range (they are properly constructed), it is at the expense of unacceptable levels of radiation towards the user`s head - unfortunately. I assure my friend Bronek that it does not matter whether the tracks of such an "antenna" are made of copper on laminate or water on concrete.


To detect the flow of CURRENT (current that does not flow does not exist) you must determine where it is flowing from. Since there is no receiver connected to the socket, unfortunately there is no flow (unless you count the leakage in the insulation resistance of the wires, if you know what it is).

To measure the current FLOWING in a wall, you would have to cut it off from other walls and connect it to them via an ammeter or cover it with clamps using the Hall effect.


The presence of a conductor at ground potential ("how can pipes block radio waves?") can block radio waves - this is how a "Faraday Cage" works

The wireless power transmission described by Sławekx can be purchased in any home appliance store under the name "induction cooker".

Congratulations on your knowledge, my friend Daroom - just notice that a changing electric field always generates a changing magnetic field, i.e. it creates radio waves


I am asking my colleague Bronek for a factual, critical answer (the alternating voltage potential is the potential of the "phase" wire relative to the ground potential - the neutral wire, it changes with a frequency of 50 Hz - what`s strange about that?)

Hello. If I were Mr. Mącia, I would call an electrician to check the cause. It doesn`t look innocent or normal if an electric field indicator was used. I had a similar, more pronounced case myself and after long-term research it turned out that the interior designer who was laying the plasterboards had drilled a phase wire in front of the differential with a long screw. The whole house was "glowing" (fazer777), and it only came out when a builder was electrocuted outside by... a metal window sill!
If the glow appears on the inductive detector - on the principle of an alternating magnetic field, then the kWh meter is its strong source and the phenomenon is normal. Regards.

If concrete is as lossy a material as you suggest, it would lose even at least VHF. And what matters here is the distance from the receiver (phazer) rather than goodness. Wet concrete is a poor conductor, and so is water, but it is not about the economy of electricity transmission and in this case the conductivity is more than enough.

I`ve heard about screens. The cables in the wall are not shielded. Shielded cables - if you read the posts, the phaser does not detect them. The screen must be at ground potential to perform the propagation suppression function. Otherwise, it is a source of secondary radiation. The screen does not heat with eddy currents but brings the potential to ground. Otherwise it would heat up nicely. The screen in which eddy currents flow at my university was not a screen. I give 100 points for an example of a structure with such a screen!

It`s strange that my friend knows that I don`t know how the phaser works, but he doesn`t bother to explain it since he knows it himself. To detect 50 Hz, I don`t have to use a half-wave antenna, just any antenna (except maybe polarization - which can be checked even in Fazer) and a bandpass filter. I will not receive the "power station" on the moon, only at a distance of a few centimeters. It`s not the phaser antenna that`s tuned, it`s the electronics.
The radio perfectly receives part of the cellular transmission when the transmitter is centimeters from the radio receiver, although it is not tuned or adapted (modulation) to the GSM frequency. A similar situation.

I`m glad that my colleague himself notices that we colloquially say "potential" instead of voltage (although correctly it should be a potential difference). It`s strange that since he notices it himself, he blames me for it. I don`t want to calculate the value of the gravitational field near a spherically symmetric mass, it`s completely O.T.

I suggest shifting the arguing about titles, university level and definitions to PW. However, I ask my friend for an explanation
1. why does an unshielded conductor causing a change in the electric field not produce an electromagnetic/radio wave? In the days of low-level colleges, it was triggering
2. how can two pieces of wire connected to a frequency of 100 MHz be an antenna and two pieces of wire in a wall connected to a frequency of 50 Hz are not
3. how does Fazer work

50 points for each reasonable answer to these questions.

Someone used the name phaser777. I have it and I will add that I have a Bosch detector (metal, wood and live cables) and what now - both of them see the electricity in the same way, only one cost about PLN 30 and the other about PLN 450. In the Bosch it is persistent because when I look for something in the wall, it also finds electricity and what is true or false, what to do with the indication, and I simply put my hand to the wall and thus ground it and the problem disappears. No problem, and there is nothing where the power cable was supposed to be

Buddy cranky, you were close, unfortunately you missed. Two methods are used to detect wires:
- magnetic field detection
- electric field detection

Why?
The intensity of the electric field and magnetic field decreases hyperbolically from the surface of the wire (thanks to this, measurement accuracy is achieved, the field value increases non-linearly in the vicinity of the wire).
Instructions for the locator with detection of both fields:
http://www.apar.pl/pdf/inst_lkz_700.pdf

Besides, my friend, Szybko Elektron, squishy electron, probably explained everything, so the topic should be closed, I guess.

Walls can have a large heterogeneity of conductivity at a low value - for example, plaster is slightly conductive (it has resistance
of the order of megaohms), and the wall itself conducts several hundred times worse; in such a situation, the current flowing through the cable capacitance (this current is
of several µA per meter of cable length) to the wall generates an alternating voltage between the wall and the ground, and on large areas of the wall
- this may make it impossible to locate the cable with the electric field sensor, because the sensor detects it almost everywhere.

cranky wrote:

Congratulations on your knowledge, my friend Daroom - just notice that a changing electric field always generates a changing magnetic field, i.e. it creates radio waves

Buddy cranky - what you write is true, but in the case in question it has no significance. The electromagnetic field from the 50Hz power supply installation is almost exclusively a reactive field. So I suggest that my friend not cause any confusion with any waves.

And by the way, my friend Cranky is causing quite a stir here with his posts, because in what he writes there are many true and completely false observations. But I don`t have time to replace them now.

Bronek22 wrote:

You`re right about detecting fields in phasers. Because these are the only two fields of any intensity that can be detected. As long as they don`t die in the disruption.
The only drawback is 50Hz which is extremely difficult to filter out.

Buddy Bronek. I have so-called cable pair locators at home. Each has a structure similar to Sonel`s LKZ, but without a magnetic field sensor (only electric field). On one of them I have a "flick" - 50Hz filtering (in this case, a stop filter). Of course, this is not a typical LC or even RC filter. It is an active RC filter of some sort (I have not looked at the construction). The fact is that it is very effective. If there is a 50Hz live wire nearby, there is silence when the filter is turned on. However, signals with other fs (e.g. 8kHz) are heard unchanged.

best regards
-DAREK-

Bronek22 wrote:

You`re right about detecting fields in phasers. Because these are the only two fields of any intensity that can be detected. As long as they don`t die in the disruption.
The only drawback is 50Hz which is extremely difficult to filter out.
The selective field detection problem is nothing more than a direct gain radio receiver.
Bronek

Is your friend writing about a super-reactive radio? Receiving "not radio waves"?
A 50 Hz filter is not that rare - see Darom`s post. LC and LR filters in miniature electronics have recently been used less frequently, and RC filters are increasingly used.
When it comes to points, your friend is wrong - the elektroda forum allows you to give points to any participant.
So I would like to thank my colleague Badryk for the explanation.

PS Bronek22: Receivers without heterodyne are not old school. I think everyone has a few pieces at home.

If you want not to miss one frequency, use an RC filter "double T" , or Wien bridge .

Hello

in fact, my colleague _jta_ reminded me of RC quads: double T filter, bridge or ladder. I once did a double T at 400Hz and it performed quite well. What I meant was to "cut off" the dial tone of the telephone exchange (what we hear after picking up the handset).

The simplest case of an active bandpass filter is an operational amplifier having a double T filter in the negative feedback.

best regards
-DAREK-

... but it is not particularly suitable for an electric field sensor - you need an impedance calculated in megohms, or an FET at the input.