Why is the signal poor in an elevator?

In order to avoid the influence of external electric fields on instruments and equipment, or to avoid the effects of the electric field of electrical equipment on the outside, cavity conductors are used to cover the external electric field so that the internal components are not affected and the electrical equipment is not external. Influential.

Because the elevator car is a metal material that is closed on all sides, this is a standard electromagnetic shielding structure。Basically all external electromagnetic signals (including cell phone signals, broadcast signals, GPS signals) are shielded and will not be received in the elevator car. Unable to send signal.

Therefore, in many commercial buildings and office buildings, signal antennas are installed in cars to help with internal and external signal transmission, and the shielding problem can be solved, and external signals can be received. Otherwise, whether the signal is very poor.

The propagation of the signal depends onElectromagnetic waves。When an electromagnetic wave carrying a signal passes through a medium, it is subject to a skin effect.

Therefore, a part of the electromagnetic waves will stay on the surface of the medium and cannot pass through the medium completely. The conductivity of the medium.

The better, the more obvious the effect of blocking electromagnetic waves.

[The signal is not afraid of insulators].

Now, let's assume that there is a wall through which electromagnetic waves will pass. If the wall is completely insulated, there will be no such wall in the electromagnetic waves. It can pass very happily without causing any loss.

[The signal is most afraid of metal].

If the wall is electrically conductive, for example, metallic from the point of view of electromagnetic waves, then this is an impassable high wall that is almost impossible to pass through. <>

elevators, some high-rise buildings.

It's poor, and now we know why? The signal in the elevator is particularly poor because the elevator is equivalent toA metal box, and some high-rise buildings use a lot of metal to increase the stability of the structure, which also leads to poor signal.

Actually, we have a lot of solutions to solve it. A number of small signal repeaters are installed in the elevators.

Because the elevator is completely a small enclosed room, it is easy to cause the signal to be blocked.

Because the elevator is a confined and small space, the signal is naturally not very good.

Because the electromagnetic field in the elevator blocks the signal, the signal is poor.

Because there will be a lot of electrostatic electric fields in the elevator, he will block the mobile phone signal.

Inside the elevator, there is basically a lot of metal that will cause the shielding. So the signal is poor.

Because the signal will be blocked a lot in the elevator, the signal is very poor.

Because the elevator also needs to use a signal to operate, it must be said that there must be no signal.

Because the elevator is a relatively closed space, and its material is also impermeable.

The reason for this is that there is a signal shielding instrument in the elevator.

Because it's a sealed space here, the signal isn't very good.

Because of the elevator structure, the elevator itself is a hollow enclosed metal space, which can shield radio waves from the physical level, and mobile phones transmit information through radio waves, so naturally there is no signal.

Generally speaking, the elevator ride time is relatively short. If you find that there is no signal, you can wait a little longer, and when you leave the elevator, you can use your mobile phone, and there will be a signal at this time.

The invention of the elevator.

In 1853, at the World's Fair at the Crystal Palace in New York, American Elisha Graves Otis presented his invention to the world for the first time. Standing on a platform full of goods, he commanded his assistant to lift the platform to a height that could be seen by the audience, and then signaled that the assistant had cut the elevator cable with a sharp axe.

Surprisingly, the elevator did not crash, but was firmly anchored in mid-air – and the elevator safety device invented by Mr. Otis came into play. "All is safe, gentlemen. Mr. Otis, who was standing on the elevator platform, waved to the people around him.

No one would have thought that this was the first safety elevator in human history.

The elevator without a signal is because the metal shell of the elevator is equivalent to a signal receiver, which absorbs most of the mobile phone network signals, so the signal strength is reduced, so the mobile phone cannot receive the signal.

The elevator with a signal has a signal coverage inside, and a small antenna has been installed in the elevator to send the mobile phone network signal directly to the elevator to maintain the signal strength, so the mobile phone can receive the signal.

Because the elevator is metal, you are in the shell of the elevator will greatly reduce the transmission of signals, if the signal outside the elevator is very good, there will be a little signal inside, if the outside signal is poor, there is basically no signal inside.

Hello, I'm sorry for the inconvenience caused to your use, as an operator we attach great importance to network construction, and have been continuously strengthening the breadth and depth of network signal coverage, because network coverage will be affected by many factors, we will strive to speed up the pace of network construction, and constantly improve the network coverage area, look forward to your continued attention and supervision, thank you!

Electrostatic shielding: In order to avoid the influence of the external electric field on the instrument and equipment, or in order to avoid the influence of the electric field of the electrical equipment on the outside world, a cavity conductor is used to cover the external electric field, so that the inside is not affected, and the electrical equipment does not affect the outside world.

The elevator is made of metal closed on all sides, which is the standard electromagnetic shielding structure, and all external electromagnetic signals (including mobile phone signals, broadcast signals, GPS signals) will basically be shielded out, and there is no way to transmit signals in the elevator car. Therefore, many business buildings and office buildings will install a signal antenna in the car to help the internal and external signal transmission, which can solve the problem of shielding and receive the signal from the outside world, otherwise the signal will be very poor or even none.

There is no signal inside the elevator for several reasons:

1) The elevator is generally located in the center of the building, and the signal is seriously blocked;

2) The elevator shaft is long and narrow, with a tunnel effect.

Leads to accelerated wireless signal loss;

3) The elevator is separated by solid reinforced concrete.

It is difficult for outdoor signals to cover the entire shaft;

4) The elevator car is a metal structure, which has a strong shielding effect on the signal.

5) Some elevators are not completely sealed, but there is also no signal. The reason is that the elevator shaft is often thicker concrete, which has a strong ability to absorb mobile phone signals, which will also lead to weak mobile phone signals, and signal amplifiers need to be installed at this time.

<> inside the elevator is a closed metal seal, the signal is blocked by the metal frame, and at the same time, there is no signal in the elevator, and there is generally no signal in the mobile phone in the sealed environment, and there will be no signal only if the signal amplifier is installed in the sealed environment.

Now mobile phones have become an indispensable part of our lives, there are many friends will have questions, why when you walk into the elevator when you hit **, there will be no signal, let's solve the questions for you, because our mobile phone is like a two-way radio.

Hello! The elevator itself is a hollow enclosed metal space, which can be shielded from radio waves on a physical level, and mobile phones transmit information through radio waves, so naturally there is no signal. Solution One:

To make the signal cover the elevator, it is necessary to build a special elevator signal distribution system, usually adding wall-mounted antennas and logarithmic antennas on both sides of the elevator, or installing antennas in the car of the elevator. The cost of this work is high, so many developers are reluctant to spend extra money. If the elevator has signal coverage, you can see obvious operator prompts in the elevator.

Nowadays, with the popularity of elevator advertising, businesses need to install a signal system to advertise on the LED screen in the elevator through the wireless network. The elevator needs to be equipped with a monitor, and the signal also needs to cover the elevator. Solution 2:

Installing a signal amplifier, some elevators are not completely sealed, but there is also no signal. The reason is that the elevator shaft is often thicker concrete, which has a strong ability to absorb mobile phone signals, which will also lead to weak mobile phone signals, and it is necessary to install Linchuang signal amplifiers at this time. That's why there is no signal in the elevator.

Nowadays, most elevators have built-in emergency help buttons, which can be pressed to help even if there is no mobile phone signal in the event of an accident. It is believed that with the advancement of technology, the signal will cover more elevators.