Cell phone jammer devices are used in many places, such as school exams, prisons, hospitals and other places. However, the choice of shielding devices is also very particular. Do you know how to choose a shielding device?
Many people know the shielding device but don't know its working principle. They just think that it is amazing to make the mobile phone lose the signal in an instant. Then we can look at the working principle of the shielding device. The mobile phone has a signal because the electromagnetic wave emitted by the signal tower is received by the electromagnetic wave of the mobile phone, and then there will be a signal. The function of the shielding instrument is that it emits an electromagnetic wave with a wavelength between the long wave and the short wave. Interfering with the mobile phone's reception of electromagnetic waves from the base station makes the information received by the mobile phone garbled, so the mobile phone cannot receive messages normally and displays the words "No Service", which achieves the effect of shielding the signal.
A good shielding instrument should be green and environmentally friendly, the electromagnetic field strength is lower than the national standard, and it is not harmful to the human body; and it only shields the mobile phone signals in the examination room, without any influence on the mobile phones outside the examination room, and will not cause interference to the signal tower. A good shielding instrument has absolute quality, and Greatjammer is a company focused on this.