When was itWireless networkThe products reached thousands of households. In public areas such as restaurants, hotels, malls, halls, squares, etc., we also wish to share information around us via wireless networks rather than using our own mobile phone traffic... Wherever we go, mobile screens show that we've received countless wifi signals. There were even claims that there was a sad cry that wifi could not be searched. Wireless web products have made it easier for people, but they have also plunged many into the fear of radiation。
In recent days, the news of “girls-in-law pregnant and men demanding that neighbours stop using wifi” has become hot. During the same period, twitter and twitter also went crazy about the news that “wifi must be shut off at night”. According to the news, about five danish female secondary school students carried out an experiment to cultivate some of the pelican seeds in rooms with and without the wifi launchers, and 12 days later it was discovered that the seeds in the ordinary room were growing normally, while the seeds in the wifi room were not growing, turned brown, some of them even dead。
Is wifi a new kind of radiation? How big is wifi's radiation? Is it really that bad? With all the questions in mind, journalists walked into the electromagnetic environment research unit of the china institute of metrology sciences, hoping to shed light on the reality of wifi's radiation through scientific measurements。
The director of wu zheng, a specialist in electromagnetic radiation measurement, had a laugh at the journalist's interest, saying that the effects of wifi radiation on human health and safety were largely negligible in normal use. However, he then told journalists, in a responsible manner, that one of the main tasks of the office of research in the electromagnetic environment was to study the effects of various types of electronic appliances on the environment and that a large number of experiments had enabled them to make such a determination so quickly. According to wu zheng, wifi is the acronym for wireless insurance, a wireless authentication technique, which may refer to wireless transmission technology that meets the iee standard of 802. 11, or equipment that meets this standard. Wifi is actually a small local area network, mainly for data transmission. And as a wireless device, which contains a transmitter, it does produce radiation around it, and the radiation from wifi is electromagnetic radiation。
In fact, electromagnetic radiation is everywhere in life and, with the exception of wifi, electrical radiation is generated by televisions, microwave stoves, printers, computers, mobile phones and wind blowers. Wu zheng told journalists that the experiment had shown that the radiation power of these appliances, which were qualified and non-damaged, was low, that the impact on the human body was minimal, and that the impact on the human body of equipment meeting the standards could even be completely ignored。
Most commonNo routerWorking power ranges from dozens to hundreds of milliwatts, which is smaller than normal mobile phones (with maximum radiopower of up to 2watts). And wifi devices, such as wifi, are much further away from users than mobile phones, which allows people to accept radiation at a much lower power density. He also indicated that the intensity and distance of the radiation was inversely equal to the square, let alone the decay of cement through the bars, at a time when the radiation value was only one tenth, or even one tenth, of the national limit. Moreover, there is no real scientific evidence that wifi, which is not fundamentally different from cell phone signals, is microwave, is generally located in a band of 2. 4 ghz, is non-ionizing radiation, and there is no real scientific evidence that it can damage human dna or protein structures, thereby affecting the development of the foetus and the health of the pregnant woman. Even mobile phone radiation is safe for normal use if its electromagnetic radiation is below the limits set by national standards. There is also no conclusive evidence of any health problems associated with wifi radiation in relation to human health。
To be more persuasive, wu zheng led journalists to the wifi radiation monitoring experiment. At the scene, senior engineer shen qing fei rigorously tested journalists. Shen qing fei opened a wireless router of an external twin antenna on the lab, and set up two notebooks a few metres away for large file transfer via a wireless router to ensure that the wireless router is operating at a high load. When everything was ready, shen qing fei placed a field force next to the antenna of the router that was working, and journalists saw the value of the field strength being around 10 volts per metre; when the field strength was placed about 30 centimeters from the wireless router antenna, the value of the field strength was rapidly reduced to 2 volts per metre; when the field strength was placed 1 metre from the antenna, the field strength showed only 0. 6 volts per metre, close to the environmental electromagnetic field。
Shen qing fei has also seen the news of the recent madness on twitter. He said that the scientific nature of the experiment could not be measured because of the lack of certainty about the specific environment, processes, methods and operating norms of the experiment. As can be seen from earlier experiments, the radiation effects of wifi are very small and, even taking into account the effects of electromagnetic radiation overlaps, are simply not sufficient to affect the gerontization of seeds. Later, journalists looked at the test report through the shell net and found that it was not wifi that the seed in the room did not germinate, with a lumber rate of 85. 3 per cent in practice and 95. 4 per cent in the room without wifi. Indeed, as shen qing fei said, there is a 10 percent gap, but there are many reasons for the seed to germinate, and it can't be assumed that wifi affected the seed germination rate. Moreover, the human body is a system that is much more complex than seeds, and the effect of wifi cannot be pushed in such a way。
What if there were multiple wireless routers in one room? Are radiation monitoring values different from plant routers? The number of antennas varies from router to router. How much has the impact changed? In addition, is the power of the utility wireless router greater? Is there a health risk? In response to a series of questions from journalists, shen qing fei explained with patience。
For different domestic routers, there will be some changes in the value of electromagnetic radiation, but whether it's an antenna or an external router, a single antenna or a multiple antenna, the electromagnetic radiation around the router meets the requirements of national standards for environmental electromagnetic radiation. If there are multiple unwired routers in the same room, multiple unwired routers can collide, and close to multiple routers (within a few centimetres) may be larger and exceed the limit of the standard for human acceptance of radiation, but since this is not a long-term area of human activity, there is usually no need to care about the size of the radiation here. Public wireless by-products, such as the unwired routers operated by the operator, are more powerful to cover more areas, but these unwieldy circuits are further away from the area where people are active, and the radiation generated in the area of human activity is already very small, so do not worry too much。
Although the results of the experiment showed that wifi had declined to a very small extent at a certain distance, there were still suggestions for people who were more sensitive to electromagnetic radiation. Because the function of the wireless router itself is to extend the network signal to the space environment, i. E. To enable users to use the network outside the fixed line, and since the wireless router does not require frequent contact setting by the user, keep as far as possible from the wireless router as possible, if conditions permit, to reduce the unnecessary radiation effects by placing the wireless router in unreachable locations, which is the most important way to reduce the risk of electromagnetic radiation. Because electromagnetic radiation decreases rapidly with increasing distance. At the same time, experts suggest that equipment that uses wifi signals, such as mobile phones, tablets, laptops, when used around us, keep them as far as possible away from sensitive parts of the body (such as the brain, eyeball, reproductive system, etc.), and that it is better to turn wifi signals off when the network is not used, so as to reduce radiation effects and save battery power。
