Let's see where electromagnetic radiation originates in apartments, houses, and we’ll point out the simplest methods of dealing with adversity. Using radio-babies, they know: radiation is dosed - they write dealers booklets. You need to carefully assess the distance to the baby. Recall that the radiation density decreases inversely with the cube of the distance. The parameter is much more important than power. Let's see what the documents say about the types and norms of electromagnetic radiation.
Electromagnetic emissions: sources and causes
Do you know why the selected wavelengths are used for communication? Delicious areas of electromagnetic radiation are taken by the military, the state. Distribution conditions are heterogeneous. For example, sonars operate at wavelengths of 20 meters. Connected frequencies are quickly quenched with water.
Why do microwave ovens, cell phones, Wi-Fi use strictly certain parts of the spectrum? Waves fade in the fog. We pay for messages to be quickly absorbed by the medium, water, the body, containing 60 - 65% of water.
As long as we hold the handset of the phone with our hands, we will gather electromagnetic energy. The principle of operation of the microwave oven. We decided to conduct an experiment: we found a contactless screwdriver indicator with light and sound alarms in the store, and we investigated the microwave oven at home. They did the following:
- The magnetron turns off at low power, overestimated modes were avoided. Radiation was minimal, less model microwave oven does not expose.
- In the first part of the experience, the microwave is plugged into an outlet, provided with a protective grounding, designed according to European standards. It is visible, the cable channel goes down from above, it is allowed by standards.
- In the second part of the experiment, an extension cord, devoid of ground lobes, was used. It turned out a violation of European standards technology. See the result caused by electromagnetic radiation.
We remind you that the contactless indicator screwdriver inside the case contains active amplifying elements working from a simple battery. Receives weak signals from external sources. The principle of operation resembles the Soviet indicator screwdriver. The phase is located by touching the current-carrying part. However, the active amplifying part introduces considerable corrections:
- Due to its high sensitivity, the probe of the contactless indicator screwdriver works, imitating the receiving antenna.
- Sensitive to the 50 Hz range due to its purpose. With the contact method, the presence of a phase is always registered, at a distance only electromagnetic radiation generated by current movement is detected. A wire with no load will not give a signal.
- Screwdriver indicator shows 2-3 sensitivity ranges( see photo).In our case, we used the maximum for greater clarity.
The results of the experiment are stunning, the action of electromagnetic radiation is represented by snapshots:
- The first photo shows: protection against electromagnetic radiation is realized by plugging the device into an outlet equipped with European standards. The housing, being grounded, forms a screen. Otherwise, half of the radiation will go out, the second harm inside the microwave oven, causing parasitic effects.
- The second photo shows: in the case of a correct connection, the indicator screwdriver at a high level of sensitivity is silent, being close to the body. It means that the level of electromagnetic radiation is negligible, the effect on the body is not observed.
- The following photo shows an old extension cord, where there is no ground lobe. Correctly set European outlet is now inactive. The result is amazing! The device gives such a strong electromagnetic field, felt at a distance of 30 cm( minimum) from the microwave. The light indication of the green light showed in the picture( it does not mean “safe”), you can deaf from the rattle-buzzer of the indicator screwdriver.
Draw conclusions. The effect of 2.4 GHz radiation on humans has long been proven( challenged by the court, the investigator’s rights are restored by the next instance), the microwave oven wavelength is the same, the energy is so great( without grounding) that it triggers the indicator at a considerable distance. Work to lay an electrician as prescribed by standards. Sockets should be equipped with ground lobes so that the equipment body suppresses the effects of electromagnetic radiation, serving as a shield.
External and internal electromagnetic fields
Do you think proper grounding saves 100% against electromagnetic radiation? Levels the lion's share. Wave a screwdriver-indicator near the wire under the current, you will see the old indication. Mistake? Not at all - the wire is not shielded, will serve as an antenna. At a distance of 5–10 cm( depending on the strength of the current), negative effects of electromagnetic radiation are traced. Conclusion: when eliminating the influence of electromagnetic radiation, do not locate sockets and wiring networks near rest areas, beds, chairs, try to be far away.
The radiation of electromagnetic waves can be almost completely suppressed by the screen. For example, choose a braided cable, more often people put metal instead of plastic corrugation into the house. The shell is grounded. We explain the origins of events. The grounded metal corrugation forms a solid screen. The resistance to the loop bus must not exceed 10 ohms. Less is better.
Radiation is powerless to penetrate the territory of an apartment. It is equally important to defend against external fields. What kind? Cellular communication, television. Inside the hull, the phone is unable to catch electromagnetic radiation, the inside of the tanker is much safer than the city park. Protect the apartment will help the enemy - a cell phone. It will serve as an indicator of the quality of the work performed. Let's say it is easy to test a microwave oven like this:
- A cell phone fits inside.
- A call is being made.
- The signal passes - the electromagnetic radiation of the phone passes the screen freely.
Worse if feedback is valid. Clearly, the call will pass, caused by the high power of the tower transmitters, if a weak telephone manages to reach the network, it is much worse. It is clear that the antennas have different sensitivities, will help to assess the degree of shielding: it catches the old phone - it is bad, it catches a new one - better. Of course, you can use the scale on the display( one lane, two), comparing the sources of electromagnetic radiation by force.
Quickly understand. Suppose the meter registers an electromagnetic field, when the door of the microwave oven is closed, the plug in a properly grounded outlet. Steel resistance is high. It is required to ground the device more carefully. Against the general background, a properly connected microwave will create much less electromagnetic radiation than in the absence of special measures.
The main source of interference, covering a significant spectrum, is considered a home personal computer. The monitor, the system unit will certainly turn on with grounding. By the way, with a screwdriver indicator it is easy to measure the degree of harmfulness of the display: the probe responds to the frame rate( 60 Hz).In the same way as they did with a microwave oven, those who wish can test the system unit, including in the standard power filter, an old extension cord without grounding for electromagnetic radiation.
Apartment types of electromagnetic radiation are exhausted. We assume that Wi-Fi-modems belong to personal computers, the duties include the emission of electromagnetic waves. Things need to be kept away: on the balcony, in the next room, for switching with the antenna to use a wired connection through a shielded cable of the radio band( characteristic impedance of 50 Ohms).The screen, as many have guessed, is grounded. The resistance measurement should be relative to the contour bus in a size of 10 ohms. Indeed, for the most part the condition is fulfilled, the screen is more often copper.
According to generally accepted standards, aluminum foil is planted on a drain drain wire. Otherwise, it will be similar to our experience with a microwave oven in the first part. When conducting tests, note that not all ranges, frequencies will be evaluated by one instrument. Screwdriver indicator responds to the frequency of 50 Hz, to work with which is designed. The phone will show results on its 1.5-2 GHz wave. Microwave, Wi-Fi networks operate at 2.4 GHz.
Properly we do the screen of protection against electromagnetic waves
In each case, a good screen will provide an excellent result by blocking electromagnetic radiation. Just measure the conduct of the appropriate tool. Remember: it is more difficult to isolate short waves. For an example, take a mirror. Performs a screen of a range of light electromagnetic waves. Completely continuous, on the radar of the circular review, the reflector is made net.
Short waves propagate over the surface of the metal, long penetrate into the thickness. For shielding the electromagnetic radiation of the 50 Hz spectrum, thick sheets of steel are used, a thin layer of foil is enough for Wi-Fi cables. The radiation of an industrial network can be stopped by a sieve, it will not work for a microwave. The main reason why cell phones continue to work inside microwave ovens. The grating gradually filters the vibrations( seeping along the surface in the area of small holes), the situation becomes worse if the door is not grounded by loops.
What to do? Try using foil. Please note that glueing inside is prohibited. There is a small chance of discharge by ionization of air. An unpleasant phenomenon, the foil will burn. If you glue the thing just outside, work to ensure reliable contact with the steel of the door. Microwave shielding is avoided as an easy task. A worthy goal - to protect the family. M Icavas are useful, convenient to quickly heat up food.