Pregnancy radiation protection is a concern for every expectant mother. Radiation-proof maternity dress is also a necessary equipment for expectant mothers. How do you identify maternity wear radiation protection effect? Use the method of wrapping the mobile phone to test the shielding effect of radiation protection clothes. Is it correct?
Does radiation protection maternity dress really protect against radiation?
Most consumers use cell phones to test the radiation protection effect of radiation-proof clothing. Each manufacturer does not guarantee that the mobile phone must have no signal in the introduction of radiation knowledge on its own website. Why does this happen?
From a consumer perspective, testing with a mobile phone is the most intuitive and least costly method of detection, and the radiation protection products on the market are able to wrap the mobile phone in most cases without signal. The power of word of mouth makes most people believe that the package The product that holds the mobile phone signal is better than the package, and this is actually a misunderstanding. Many people believe that since the electromagnetic shielding suit is used to shield electromagnetic waves, it can shield the mobile phone signals and cannot be shielded. The effect is certainly poor. This view is not entirely correct.
Whether the mobile phone has a signal and the geographical location of the mobile phone, the frequency band of the network where the mobile phone is located, and the sensitivity of the mobile phone itself have a great relationship. From the mobile phone base station is far away, the frequency band of the mobile phone is subject to a large degree of interference (the degree of CDMA interference will be less than GSM), the sensitivity of the mobile phone itself is low, and the probability of enveloping the mobile phone without a signal is relatively high, and conversely, the probability is small. In particular, the last point, the sensitivity of mobile phones, in theory, the sensitivity of mobile phones can be very high, with the development of science and technology can even be infinitely high, so that as long as there is a signal can be received, the new high-end mobile phones emerge one after another, Therefore, no radiation protection company can guarantee that its products will not contain any signals in any case.
Secondly, the signal of the mobile phone is good or bad, and as far as we know, the reason why the mobile phone can receive signals everywhere is because the signal conversion (increase) device is installed on some high buildings, so we can use it wherever If a cell phone calls, then the cell phone signal is stronger near the cell phone signal converter (increase) device, and the signal is not good if it is far away from the cell phone signal converter (amplifier) ​​device.
Therefore, it is an erroneous and unscientific approach to use mobile phones to test whether or not to make a call. Especially in some of the larger shopping malls and OFFICE buildings, because the structure of those buildings caused all the mobile phone signals inside to be very poor, mobile phone signal enhancement instruments were installed on the top of the building, so these large shopping malls In the test, it can not reflect whether it is really shielding effectiveness.
Consumers are constantly pursuing radiation protection products that have no signal for mobile phones, and will allow some unscrupulous manufacturers to take advantage of it. There will be some manufacturers in the design of radiation protection products designed specifically for mobile phones, such as adding harmful elements in the metal fiber in order to increase the effectiveness of shielding mobile phone signals, at present we know that some companies with higher chromium content The thick metal fibers to woven into the clothes, this radiation protection maternity dress can completely shield the mobile phone signal, but this radiation protection maternity dress on the computer, television and other other commonly used radiated electrical effects reduced, can be said to have no effect In addition, there are irregularities in the weave of metal fibers in the textile process. Irregular metal fibers, when they encounter electromagnetic waves, will generate new electromagnetic waves to interfere with the original electromagnetic waves, thus temporarily increasing the frequency of operation of mobile phones. The degree of interference makes it easier for mobile phones not to receive signals. Actually more mobile phone signals are transformed into other messy radiation. Irregular weaving makes it easier for the radiation-proof fabrics to be lax and is not conducive to long-term radiation protection.
In addition, the electromagnetic wave has both near field and far field field radiation, and is mainly distinguished by the wavelength radius of the electromagnetic wave. Among them, near field radiation is harmful to the human body. Taking a mobile phone as an example, the mobile phone itself emits electromagnetic waves, and the mobile phone signal base station also emits electromagnetic waves. However, the human body and the mobile phone are basically in “zero-distance contactâ€. The radiation received by the near field is the most harmful, and the distance between the human body and the mobile phone base station is generally Above 20 meters, only the far field radiation is accepted, and the radiation intensity meets the national standard, basically no harm to the human body. The shielding of mobile phone signals shields the far-field radiation emitted by mobile phone base stations, which is of little significance.
The radiation protection equipment can effectively shield the radiation in the near field, and also can shield the far field radiation effectively. In some places, the mobile phone can still be connected. There are several reasons for this:
1. The mobile phone has the function of actively searching for signals, and different mobile phones have different strengths. In the same location, different phone tests may result in different results.
2. Your mobile phone's transmitting base station is very close to your test place. The power density emitted by the transmitting base station is very high, so there is still a weak signal that is being searched by the mobile phone.
3. Different base stations emit different power at different time intervals.
4, some brands of mobile phone radiation, the received signal power is strong, it may also be searched in the shielded signal. Therefore, some mobile phone manufacturers and communication companies on the market emphasize low radiation, safety, and environmental protection rather than pursuing the powerful receiving and transmitting functions of mobile phones.
5. There may be cases where the experimental method is incorrect. The tiny gaps will also have signal leakage. When packing, it is necessary to pack the phone around the camera tightly and wait for a while.
6. It is related to the direction of the mobile phone antenna and the base station during testing, and the probability of the antenna being entrapped when facing the base station is large.
7. If you test in a room, depending on where you are located, there is a high probability of being surrounded when standing near a load-bearing wall, because the load-bearing wall is a reinforced concrete structure, which can play a certain shielding effect against external signals.
8. The signal indication on the mobile phone panel is actually controlled by software. The signal number of different mobile phones represents different meanings, and the difference between the signal indication of some mobile phones and the actual signal strength is still relatively large.
Therefore, the visual inspection of the completely or partially shielded mobile phone signal is only a simple method of detecting whether the product has efficacy, and is not a product qualified testing standard. Because the mobile phone is a search signal, there are many interference factors. Only the test results obtained at the same time, in the same place and in the same direction, with the same mobile phone, and wrapped for the same time are comparable. Shielding efficiency is less than 100% (100% fully shielded products cannot be made into garments), there is still signal leakage, and the phone may be switched on.
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