Why is there no signal in the elevator?

I. Elevator Structure

The elevator itself is a hollow closed metal space, which can physically shield radio waves, while the mobile phone transmits information through radio waves, and naturally there is no signal.

Second, the signal does not cover this area.

In order to make the signal cover the elevator, it is necessary to build a special elevator signal distribution system, usually installing wall-mounted antennas and logarithmic antennas on both sides of the elevator, or installing antennas in the elevator car. 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 popularization of elevator advertisements, merchants need to install a signal system to put advertisements on the LED screens in elevators through wireless networks. Recently, elevator crimes are frequent, so elevators need to be equipped with monitors and signals to cover elevators.

Third, no signal amplifier is installed.

Some elevators are not completely sealed, but there is no signal. The reason is that the elevator shaft is often thick concrete, which has a strong ability to absorb mobile phone signals, which will also lead to weak mobile phone signals. At this time, it is necessary to install a signal amplifier.

Extended data

Instructions for safe use of elevator:

(1) When using the elevator, please press the up button if you want to go upstairs, and press the down button if you want to go downstairs.

(2) After the elevator arrives at the floor, passengers should determine the running direction of the elevator; When it is determined that the running direction of the elevator is consistent with its own direction, it will enter the car again.

(3) Passengers can close the elevator door by pressing the "close button" on the operation panel in the elevator; Elevator doors will also automatically close at regular intervals. Passengers should not stay at the joint between the floor and the carriage to avoid being pinched.

(4) After passengers enter the car, determine the elevator stop floor by pressing the floor selection button. Passengers are not allowed to lean against the door.

(5) The elevator has the rated passenger capacity standard. When people are overloaded, the alarm device in the elevator will give a sound prompt. At this point, passengers should take the initiative to reduce staff and exit the elevator.

(6) When the elevator has abnormal phenomena or faults, passengers should keep calm, and can call the alarm phone in the car for help or wait for rescue. Never pry open the door without authorization in an attempt to escape from the car.

(7) Keep the car clean, don't smoke in the car, and don't litter everywhere.

(8) Passengers should take good care of elevator facilities, and are not allowed to press buttons or pry the doors.

Managers should strictly perform their duties and regularly check the operation of elevators; And make daily maintenance inspection records, contact elevator maintenance regularly, and make maintenance records; Handle and report faults in time.

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