Cell phone signal blockers are not harmful to the human body. The following is a specific analysis:
Principle harmless: cell phone signal shielding instrument based on electromagnetic wave signal can not penetrate the characteristics of metal objects work. When the phone is placed in the shield, the signal can not penetrate the metal, so as to achieve the effect of shielding. This principle determines that the shielding instrument is harmless to the human body, because it does not produce radiation or substances harmful to the human body.
No direct effect on the human body: placing a cell phone into the shield will not cause any harm to the human body even if the phone is not turned off. The shield simply prevents cell phone signals from being received and sent without negatively affecting human health.
Potential impact on cell phones: Although shielding devices are not harmful to the human body, they can have a potential negative impact on cell phones. For example, when a cell phone cannot receive a signal, it will automatically increase the signal reception power to try to get a signal, which may lead to accelerated power consumption of the cell phone battery and affect the performance of the cell phone.
In summary, cell phone signal blockers are harmless to humans under normal use, but attention should be paid to their possible impact on cell phone performance when used.
Translated with DeepL.com (free version)
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