All inhabitants of the earth are in the zone of action of various radiations. To natural sources (solar radiation, radiation background of the earth, electromagnetic waves of atmospheric phenomena), the human body is adapted, this is a normal habitat. But artificial radiation generators are a problem for the body.

What sources of electromagnetic field (EMF) are around

• Wiring: creates an electromagnetic field around itself, the magnitude of which is directly proportional to the load on the line. That is, when you turn on the boiler or electric oven, the radiation intensity increases many times over.
• Any electrical appliance that has conductors in its composition (windings of transformers, filaments of a hair dryer or a heater are a source of radiation). Even if there are no obvious nodes generating radiation.
• Information display devices: TV screens, monitors, tablets, laptops, game consoles.
• Acoustic systems.
• Electric motors ( washing machine, refrigerator, vacuum cleaner, fan, the same hair dryer).
• Electronic measuring instruments: electricity meters.
• Places of concentration of electrical wiring: electrical panels, TV or Internet cable switching units.
• Electrical appliances containing impulse blocks food (starting from charger for a smartphone, ending with a computer and a music center).
• The "warm floor" system, powered by electric current.
• Electrical central heating systems.
• Modern economical lighting devices (incorporate power supplies operating at high frequency).
• Microwave (MW) ovens, or electric ovens with a high-frequency heating unit. This is the scourge of modern civilization: a similar device is available in almost every home.

Separately, we list the sources of direct radiation for information transmission

• Mobile phones, smartphones, tablets with wireless connection to the network.
• Radiotelephones of the urban communication network.
• Portable radio stations.
• all sorts of wireless devices: headphones, computer mice, keyboards.
• Radio-controlled toys.
• WiFi routers.

And these are just the devices that surround us in the room. That is, located in close proximity. We can somehow influence this danger by optimizing the modes of use. In this case, protection against electromagnetic waves is within the responsibility of the building owner.

Outdoor sources of radiation

We will not talk about radiation: (nuclear plants, ships, submarines with a nuclear reactor). As well as places of production, processing and disposal of nuclear fuel and weapons. In these regions, the level of radioactive exposure is controlled by special services. Only the choice depends on us: to be in this place or not (accommodation, service, work).

Such zones have the character of point placement, in contrast to the sources of electromagnetic waves.

• Transformer substations.
• Power lines (overhead and underground). Just like in room wiring - level electric field depends on the load on the line.
• Transmitting antennas: TV towers, radio transmitters, departmental transmitting centers (military, ports, air traffic control).
• Large enterprises that use large-scale electrical equipment.
• Trolleybus lines (unlike power lines, they are located close to places of residence).
• Actually, urban transport on electric traction (at the moment when we directly use it).
• Street lighting, advertising LED screens.

All of the above does not mean that each of us is exposed to mortal danger every second. However, we must know how to protect ourselves from EMF. Or at least minimize its impact on the body. To do this, it is not at all necessary to use special means of protection against electromagnetic radiation.

How to protect yourself from the electromagnetic field in everyday life

Why at home? Special services operate at enterprises where personnel are exposed to electromagnetic fields. Their area of ​​responsibility includes:

• Measurement of the EMF level in places where people are present.
• Ensuring a safe level of radiation from sources that cannot be turned off while personnel are in the immediate vicinity.
• Control over the time spent by workers in areas with a dangerous level of radiation.
• Development guidelines and requirements when working in the EMF impact zone.

The activities of such services are supervised by supervisory authorities. And for us, you only have SES standards, and common sense when using household electrical appliances.

What methods of protection against electromagnetic radiation can be applied at home? There are three main areas of protection:

time protection

Many people remember how the consequences of the accident at the Chernobyl nuclear power plant were eliminated. Rescuers worked according to a strictly controlled schedule: the body can tolerate a certain dose of radiation relatively safely. It's like sunbathing on the beach: the time for sunbathing is regulated by doctors. Otherwise, the consequences can be sad.

The same applies to radiation from electrical appliances. General principle such:

• If the appliance is not in use, it should be turned off.
• If the device cannot be turned off, reduce the time spent in the radiation zone.

Practically it looks like this:

Protection by distance and direction

This method is both easy and difficult to follow. If you know exactly where the active radiation source is located, stay as far away from it as possible. In the global understanding of the problem, one should not purchase housing in the area of ​​power lines, on the first line from city streets (with trolleybus wires), in close proximity to industrial facilities or transformer substations.

Additional protection against electromagnetic radiation

Of course, we will not discuss metallic meshes for carrying a mobile phone in your pocket, or mythical radiation neutralizers in the form of jade pyramids. These "remedies" were popular during the wild market era of the 90s. Various active "jammers" are also nothing more than an effective means to extract money from the client. In addition, any electrical appliance, and even more so with an emitter, is another source of electromagnetic waves.

Important!
From the point of view of the theory and practice of the propagation of radio waves (as well as any other electromagnetic radiation), the only way protection is a conductive screen, grounded in accordance with the Electrical Installation Rules.

How to apply the method in practice

True, these means of protection have a side effect: a signal does not break through such walls and windows. cellular communication. Radio and TV broadcasts will also be received only on an external antenna. Considering the health benefits, this is not a problem.

• And household appliances located inside must be connected to the ground bus. Most electrical equipment has a metal case (even plastic TVs and stereos at first glance have a conductive frame inside). The level of radiation from grounded equipment approaches zero.

How to know if you are at risk from EMF radiation

Forewarned is forearmed. Try to find out as accurately as possible everything about your electrical appliances in terms of exposure to an electromagnetic field. You may need to invite SES specialists. The cost of detecting malicious devices will pay off in maintaining health.

This applies to your home. On the territory of common use, as well as at enterprises (in offices), sanitary standards apply. If you have a suspicion that these norms are being violated (unmotivated deterioration, interference on the TV, music player) - contact the SES department. Either you will receive a comforting answer that nothing threatens your health, or the responsible authority will take measures to eliminate the danger.

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1. Organizational activities include:

Removing the workplace from the EMF source ( remote control);

Rational placement in the working room of equipment that emits electromagnetic energy;

Establishment of rational modes of operation of equipment and maintenance personnel.

2. Engineering activities include:

Reducing the intensity and density of the EMF energy flux by matching loads and power absorbers;

Screening of workplaces;

Application of warning signaling (light, sound).

3. Personal protective equipment includes: overalls made of metallized fabric, protective gowns, aprons, capes with hoods, gloves, shields, goggles.

Highest Protection Efficiency from EMF can be achieved by localizing the electromagnetic field of a radio engineering device using a housing, as well as using a screen.

Protective screens, depending on the purpose, are distinguished into:

Reflective radiation (solid metal screens made of steel and aluminum, metal meshes, metallized fabrics);

Absorbing radiation (from radio absorbing materials).

The depth of EMF penetration into the screen is small, therefore, for reasons of strength, any screen is made with a thickness of at least 0.5 mm. Screen sheets must be securely connected to each other, providing electrical contact. Screens must be grounded.

If high-frequency installations are located in a common production building, then they must be installed in specially designated corner rooms. With a power of up to 30 kW, the installation should be located on an area of ​​​​at least 25, and over 30 kW - more than 40. The room must be equipped with general ventilation. Air ducts, in order to avoid high-frequency heating, are made of asbestos cement, textolite, getinaks. Radiation from the installation must not penetrate walls, ceilings, window frames and doors.

Similarly, from external radiation (from broadcast antennas, television, radar), people in the building must be protected.

If buildings fall into the danger zone, then it must be taken into account that the elements of the building reduce the impact of EMF by 2.5 - 10 times (Table 2.2).

Table 2 - Attenuation of microwave electromagnetic radiation

building structures

Forest plantations located in close proximity to radiation sources weaken EMF by 2-4 times.

If EMF attenuation by building structures is not sufficient, then the walls, ceiling, window and door openings, and ventilation system should be shielded in the room. Screens are mounted by attaching steel or duralumin sheets to the surfaces of the room. Also, shielded cabins assembled from steel shields can be used.

To eliminate the reflection of electromagnetic waves, radio-absorbing materials are used in the form of thin rubber mats, perlon sheets or wood impregnated with the appropriate composition. They are glued or attached to the base of the screen structure with special brackets.

In cases where the above methods of protection against microwave radiation do not give a sufficient effect (for example, when setting up devices), it is necessary to use personal protective equipment (protective coats, aprons, shields, goggles). If the radiation has an intensity of more than 10, then it is necessary to use glasses even for short-term work.

Spectacles of the ORZ-5 type are made of glass coated with a layer of semiconductor tin oxide. In the microwave range, they attenuate the radiation power by a factor of 1000.

In everyday life, electrical equipment, over time, may decrease the degree electromagnetic protection. So, the appearance of micro-slits in the door seal occurs due to the ingress of dirt, mechanical damage. Therefore, the door and its seal require careful and meticulous care. The term of guaranteed durability of protection against EMF leaks during normal operation is 5-6 years.

Taking into account the specifics of the radiation of a microwave oven, it is advisable, when it is turned on, to move away at a distance of at least 1.5 meters.

on the topic: Protection from microwave radiation

Goal of the work

• 1) get acquainted with the characteristics of electromagnetic radiation and regulatory requirements for its levels;
• 2) to measure the intensity of electromagnetic radiation in the microwave range on different distances from the source;
• 3) evaluate the effectiveness of protection against microwave radiation using screens made of various materials. magnetic field radiation protection
• 1. Theoretical part

An electromagnetic field is a special form of matter through which an interaction is carried out between electrically charged particles. The electric field is characterized by intensity E, V/m; the magnetic field is characterized by the intensity H, A/m, or the magnetic flux density B, T.

Table 1. Remote control of microwave radiation

The appearance of the stand for holding L.R. No. 1 is shown in Figure 1.

Rice. 1. Laboratory stand "Protection against microwave radiation BZh 5m"

A household microwave oven is used as a source of microwave radiation.

The stand is a laboratory table 1, on which a microwave oven 2 is placed, a rack 5 with a sensor 4 of an energy flux density meter (hereinafter referred to as the sensor), nodes 6 of the installation are replaceable protective screens.

The table is made in the form of a welded metal frame with a table top, on the surface of which a coordinate grid 3 with the image of the X and Y axes is applied using Jet Laser self-adhesive paper.

The stand provides three degrees of freedom of movement of the sensor (movement along the X, Y, Z axes), which makes it possible to investigate the radiation from the front panel of the microwave oven (the place of the most intense radiation) and over the entire area of ​​the coordinate grid.

As a load in the microwave oven, a refractory fireclay brick is used, mounted on a fixed stand, which is used as a shallow faience plate, which ensures the stability of the measured signal (the rotating table and the roller ring are removed from the oven beforehand).

The sensor 4 is made in the form of a half-wave vibrator at a frequency of 2.45 GHz, mounted on a rack 5 with the ability to move vertically (Z axis), made of a dielectric material.

Nodes 6 installation of replaceable protective screens provide operational installation and screen replacement 7. Replacement screens have one standard size. Screens are made of the following materials: metal mesh, metal sheet, rubber, high-impact polystyrene.

As measuring instrument multimeter 8 is used, which is located on the free part of the tabletop (outside the coordinate grid).

2. Practical part

Measurement results

Table 2. Results of radiation intensity measurements

Table 3 Shielding Efficiency

Conclusion

As a result laboratory work the characteristics of electromagnetic radiation and regulatory requirements for its levels were studied, the intensity of electromagnetic radiation in the microwave range was measured at various distances from the source, and the effectiveness of protection against microwave radiation using screens made of various materials was evaluated. As a result of measurements, it was found that the most effective protective materials are a metal screen, metal fine mesh and PVC, while rubber proved to be the least effective. Microwave radiation at a distance of 40 cm is optimal.

Answers to control questions: 1 question.

Main characteristics of EMF. What parameters characterize EMF in the "near" and "far" zones? An electromagnetic field is a special form of matter through which an interaction is carried out between electrically charged particles. The electric field is characterized by intensity E, V/m; the magnetic field is characterized by the intensity H, A/m, or the magnetic flux density B, T. The physical reasons for the existence of an electromagnetic field are related to the fact that a time-varying electric field with strength E generates a magnetic field H, and a changing H generates a vortex electric field: both components E and H, continuously changing, excite each other. The EMF of stationary or uniformly moving charged particles is inextricably linked with these particles. With the accelerated movement of charged particles, the EMF "breaks away" from them and exists independently in the form of electromagnetic waves, not disappearing with the removal of the source (for example, radio waves do not disappear even in the absence of current in the antenna that emitted them). Electromagnetic waves are characterized by wavelength l, m, or frequency f, Hz. For vacuum, the relation l \u003d c / f is true, where c is the speed of light in vacuum, equal to 3 x 108 m / s. In the field of EMF frequency classification, a strictly limited range should be noted - from 0 Hz (static fields) to 300 GHz. Although infrared, light, ultraviolet, X-ray radiation (and beyond) also have an electromagnetic nature, as a rule, EMF is understood as electromagnetic fields and oscillations in the marked range. To date, three frequency scales are in use: - "radio" as set out in the Radio Regulations; - "medical" given in WHO documents; - "electrotechnical", proposed by the International Electrotechnical Committee (IEC), which is the most common. According to the third scale, the classification of EMF is as follows: - low-frequency (LF) - from 0 to 60 Hz; - mid-frequency (MF) - from 60 Hz to 10 kHz; - high-frequency (HF) - from 10 kHz to 300 MHz; - microwave (SHF) - from 300 MHz to 300 GHz. According to the energy spectrum, EMFs are divided into the following groups, originally divided in the theory of electromagnetic compatibility: sinusoidal (monochromatic); modulated; impulse; fluctuation (noise). When characterizing the EMF impact zones, in all studies, as a rule, monochromatic fields are considered. Denoting the wavelength of the EMF l, at a distance from the source r, there are three zones of influence: 1) near (induction zone): l / r>> 1; 2) intermediate (resonant): l / r ? 1; 3) far (wave, or quasi-optical): l / r< < 1. Важная особенность ЭМП - это деление его на так называемую "ближнюю" и "дальнюю" зоны. В "ближней" зоне, или зоне индукции, на расстоянии от источника r < л, ЭМП можно считать квазистатическим. Здесь оно быстро убывает с расстоянием, обратно пропорционально квадрату (кубу) расстояния от источника r2 (r3). В "ближней" зоне излучения электромагнитная волна еще не сформирована. ЭМП в зоне индукции служит для формирования бегущих составляющих поля, ответственных за излучение (электромагнитной волны). Для характеристики ЭМП в ближней зоне измерения напряженности электрического поля Е и напряженности магнитного поля Н производятся раздельно. "Дальняя" зона - это зона сформировавшейся электромагнитной волны, начинается с расстояния r >3 l. In the "far" zone, the field intensity decreases in inverse proportion to the distance to the source r. In the "far" zone of radiation there is a relationship between the values ​​of E and H: E = 377N, where 377 is the wave impedance of the vacuum, Ohm. In Russia, at frequencies above 300 MHz to 300 GHz (microwave range), the PES electromagnetic energy flux density, W / m2, or the Poynting vector is measured. PES characterizes the amount of energy carried by an electromagnetic wave per unit time through a unit surface perpendicular to the direction of wave propagation. The higher the radiation frequency f (respectively, the shorter the wavelength l), the greater the energy of the radiation quantum. The relationship between energy Y and frequency f of electromagnetic oscillations is defined as Y \u003d h f, where h is Planck's constant, equal to \u003d 6.6 x 10 34 W / cm 2. Thus, EMF in the far (wave) zone is characterized as electromagnetic radiation (EMR ), or microwave radiation, and its intensity is defined as PES in W/m2 (mW/cm2, µW/cm2).

Answer to question 2

Norms of exposure to microwave radiation on workers and the public. The Russian regulatory documents that establish the maximum permissible levels (MPL) of EMR are the State Standards of the System of Occupational Safety Standards (SSBT) and Sanitary Rules and Norms (SanPin) that exist in parallel. Hygiene standards and norms have traditionally been developed for two categories of exposure - occupational, i.e. exposure at workplaces, and non-professional - exposure of the population, professionally not associated with the use of EMF. Recently, another category has been formed - occupational exposure of a special contingent of the population. It primarily includes women in a state of pregnancy and persons under the age of 18; for these individuals in modern Russian standards fairly rigid remote controls are installed. Foreign standards are developed mainly on the basis of experimental and computational methods, and conclusions are drawn on the basis of acute experiments with pronounced damage to the biological object. This approach made it possible to perform continuous normalization over the entire EMF range from 0 Hz to 300 GHz. In a number of foreign standards, special remote controls are also installed for people with implanted pacemakers. Biophysical basis for the development of domestic normative documents Two groups of bioeffects served, in addition to "short-term thermal": - cumulation of the effect of exposure in the body during long-term continuous and fractional exposure, especially within pre-thermal levels; - reversibility of effects and adaptation of the irradiated organism in the presence of long pauses between exposures. Such an approach required a significant amount of biomedical research and did not allow interpolating the normalization results to other frequency ranges. This, in particular, explains the discontinuous (stepped) nature of domestic remote controls, which, moreover, do not cover the entire frequency range from 0 Hz to 300 GHz. It should be noted that the pace of development of technology is significantly ahead of the pace of development of domestic standards and norms. PES remote control in the frequency range above 300 MHz to 300 GHz, according to SanPiN 2.2.4.1191-03 "Electromagnetic fields in production conditions", are presented in Table 1. Table 1 Microwave radiation remote control Category of exposed persons Flux density energy of microwave radiation, μW/cm2 Working with radiation sources during an 8-hour shift 10 Not more than 2 hours per shift 100 Not more than 20 minutes per shift 1000 Persons not professionally associated with radiation sources 1 Population 1 Assessment and regulation of exposure EMF in the frequency range above 30 kHz to 300 GHz, including microwave EMR, is carried out according to the magnitude of the energy exposure (EE).Energy exposure in the frequency range above 300 MHz to 300 GHz is calculated by the formula:

EEpe = PES x T, (W/m2) h, (µW/cm2) h, (1) where PES is the energy flux density (W/m2, µW/cm2); T - exposure time per shift (hours). The EE remote control in the frequency range above 300 MHz to 300 GHz at workplaces per shift should not exceed 200 μW/cm2 x hour.

• 3 question. Organizational and therapeutic and preventive measures to protect against EMF. Organizational measures in the design and operation of equipment that is a source of EMF or objects equipped with sources of EMF include: - selection of rational modes of equipment operation; - allocation of EMF impact zones (areas with EMF levels exceeding the maximum allowable, where operating conditions do not require even a short stay of personnel, should be fenced off and marked with appropriate warning signs); - location of workplaces and routes of movement of service personnel at distances from EMF sources that ensure compliance with the remote control; - repair of equipment that is a source of EMF, outside the zone of influence of EMF from other sources (if possible); - compliance with the rules safe operation EMF sources. Time protection is used when it is not possible to reduce the radiation intensity at a given point to the maximum allowable level. The current remote control provides for the relationship between the intensity of the energy flux density and the exposure time. Distance protection is used if it is impossible to weaken the EMF by other measures, including time protection. Protection by distance is the basis of radiation regulation zones to determine the necessary gap between EMF sources and residential buildings, office premises, etc. For each installation that emits electromagnetic energy, sanitary protection zones must be determined in which the intensity of the electromagnetic field exceeds the maximum permissible level. The boundaries of the zones are determined by calculation for each specific case of the placement of the radiating installation during their operation at the maximum radiation power and are controlled using instruments. In accordance with GOST 12.1.026-80, radiation zones are fenced off or warning signs are installed with the inscriptions: “Do not enter, it is dangerous!”. In order to prevent and early detection of changes in the state of health, all persons professionally involved in the maintenance and operation of EMF sources must undergo preliminary admission and periodic preventive medical examinations in accordance with applicable law. Persons under the age of 18 and pregnant women are allowed to work under the influence of EMF only in cases where the intensity of EMF at the workplace does not exceed the MPC established for the population.
• 4 question. Engineering and technical methods and means of protection against EMF. Engineering and technical measures should ensure the reduction of EMF levels at workplaces through the introduction of new technologies and the use of collective and individual protective equipment (when the actual levels of EMF at workplaces exceed the MPCs established for industrial impacts). In order to reduce the risk of the harmful effects of EMF created by means of radar, radio navigation, communications, including mobile and space communications, the heads of organizations must provide employees with personal protective equipment. Engineering and technical protective measures are based on the use of the phenomenon of shielding of electromagnetic fields directly in the places where a person is located or on measures to limit the emission parameters of the field source. The latter, as a rule, is used at the stage of development of a product that serves as a source of EMF. Radio emissions can enter rooms where people are located through window and door openings. Metallized glass with shielding properties is used for screening of viewing windows, windows of rooms, glazing of ceiling lights, partitions. This property is given to glass by a thin transparent film of either metal oxides, most often tin, or metals - copper, nickel, silver, and combinations thereof. The film has sufficient optical transparency and chemical resistance. Being deposited on one side of the glass surface, it attenuates the radiation intensity in the range of 0.8 - 150 cm by 30 dB (1000 times). When the film is applied to both glass surfaces, the attenuation reaches 40 dB (by a factor of 10,000). To protect the population from exposure to electromagnetic radiation in building structures, a metal mesh, metal sheet or any other conductive coating, including specially designed building materials, can be used as protective screens. In some cases, it is sufficient to use a grounded metal mesh placed under the facing or plaster layer. Various films and fabrics with a metallized coating can also be used as screens. In recent years, metallized fabrics based on synthetic fibers have been obtained as radio shielding materials. They are obtained by chemical metallization (from solutions) of tissues of various structures and densities. Existing production methods allow you to adjust the amount of deposited metal in the range from hundredths to units of microns and change the surface resistivity of tissues from tens to fractions of an ohm. Shielding textile materials are thin, lightweight, flexible; they can be duplicated with other materials (fabrics, leather, films), they are well combined with resins and latexes.
• 5 question. What determines the effectiveness of the protective screens used? The effectiveness of protective equipment is determined by the degree of weakening of the EMF intensity, expressed by the shielding coefficient (absorption or reflection coefficient), and should ensure that the radiation level is reduced to a safe level within the time determined by the purpose of the product. The assessment of the safety and effectiveness of protective equipment should be carried out in testing centers (laboratories) accredited in the prescribed manner. Monitoring the effectiveness of collective protective equipment in the workplace should be carried out in accordance with specifications but at least once every 2 years; personal protective equipment - at least once a year.

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Is microwave dangerous to human health: truth or myth?

When microwave ovens first appeared, they were jokingly called bachelor appliances. If you follow this statement, then it is true in relation to the first generation of kitchen appliances. However, at present, microwave ovens are equipped with a number of functions and unique features that deserve respect. It is very easy to control the device using a processor that works according to the set parameters. That is why it is important to familiarize yourself with all the nuances of such a technique in order to make sure what effect it has on the human body.

Physical characteristics of operation

Over the past few years, you can observe a boom in microwaves. The harm of a microwave oven is not a myth, but a strict reality, which has been proven by doctors and scientists. This opinion is supported by materials, scientific evidence of which confirms the negative impact of microwaves on the human body. Long-term scientific studies of radiation from microwave ovens have established the level of harmful effects on human health.

That's why it's important to stick to the rules. technical means protection or tso. Protective measures will help reduce the power of the pathogenic effect of microwave radiation. If you do not have the opportunity to provide optimal protection at the time of using the microwave for cooking, you are guaranteed a harmful effect on the body. It is very important to know the basics of TCO and apply them in the work in the microwave.

If we recall the basic course of physics in the school curriculum, we can establish that the heating effect is possible due to the work of microwave radiation on food. Whether you can eat such food or not is a rather difficult question. The only thing that can be argued is that there is no benefit to the human body from such food. For example, if you cook baked apples in a microwave oven, they will not bring any benefit. Baked apples are exposed to electromagnetic radiation, which operates in a certain microwave range.

The radiation source of microwave ovens is the magnetron.

The frequency of microwave radiation can be considered the range of 2450 GHz. The electrical component of such radiation is the effect on the dipole molecule of substances. As for the dipole, it is a kind of molecule that has opposite charges at different ends. The electromagnetic field is capable of turning a given dipole one hundred and eighty degrees in one second at least 5.9 billion times. Given speed this is not a myth, so it causes molecular friction, as well as subsequent heating.

Microwave radiation can penetrate to a depth of less than three centimeters, subsequent heating occurs by transferring heat from the outer layer to the inner one. The brightest dipole is considered to be a water molecule, so food that contains liquid heats up much faster. The vegetable oil molecule is not a dipole, so they should not be heated in a microwave oven.

The wavelength of microwave radiation is about twelve centimeters. Such waves are located between infrared and radio waves, so they have similar functions and properties.

Microwave Danger

The human body is capable of being exposed to a wide variety of radiation, so the microwave oven is no exception. You can argue for a long time about whether there is any benefit from such food or not. Despite the huge popularity of this kitchen appliance, the harm from the microwave is not a fiction or a myth, so you should listen to the advice on TCO, and also, if possible, refuse to work with this stove. During use, you need to monitor the status of the indicator.

If you do not have the opportunity to protect the body from harmful energy, you can use high-quality protection, the basics of TCO, to protect your own health.

First you need to find out the risk that the radiation of a microwave oven can carry. Many nutritionists, doctors, and physicists are incessantly arguing about food prepared in this way. Ordinary baked apples will not do any good, as they are exposed to harmful microwave energy.

That is why every person should become familiar with the possible negative health effects. The greatest harm to health from a microwave oven is in the form of electromagnetic radiation that comes from a working oven.

Negative for the human body side effect can become deformation, as well as the restructuring and collapse of molecules, the formation of radiological compounds. In simple words, there is irreparable damage to the health and general condition of the human body, since non-existent compounds are formed, which are affected by ultra-high frequencies. In addition, one can observe the process of water ionization, which transforms its structure.

According to some studies, such water is very harmful to the human body and all living things, as it becomes dead. For example, when watering a living plant with such water, it will simply die within a week!

That is why all products (even baked apples) that are thermally processed in the microwave become dead. According to such information, we can sum up a little, food from the microwave has an adverse effect on the health and condition of the human body.

However, there is no exact argument that can confirm this hypothesis. According to physicists, the wavelength is very short, so it cannot cause ionization, but only heating. If the door opens and the protection does not work, which turns off the magnetron, then the human body is affected by the generator, which guarantees harm to health, as well as burns to internal organs, since the tissue is destroyed, it is under serious stress.

To protect yourself, protection must be at the highest level, so it is important to stick to the tso base. Do not forget that there are absorbing objects for these waves, and the human body is no exception.

Impact on the human body

According to studies of microwave rays, when they hit the surface, the tissue of the human body absorbs energy, which causes heating. As a result of thermoregulation, there is an increase in blood circulation. If the irradiation was general, then there is no possibility of instantaneous heat removal.

Blood circulation performs a cooling effect, so those tissues and organs that are depleted in blood vessels suffer the most. Basically, clouding occurs, as well as the destruction of the lens of the eye. Such changes are irreversible.

The fabric with the highest absorbency has the highest absorbency. a large number of liquids:

• blood;
• intestines;
• mucous membrane of the stomach;
• lens of the eye;
• lymph.

As a result, the following happens:

• the efficiency of the exchange, adaptation process decreases;
• the thyroid gland, blood is transformed;
• the mental realm changes. Over the years, there have been cases where the use of the microwave causes depression, suicidal tendencies.

How long does it take for the first symptoms of a negative impact to appear? There is a version according to which all signs accumulate for a long time.

For many years they may not appear. Then comes the critical moment when the general health indicator loses ground and appears:

• headache;
• nausea;
• weakness and fatigue;
• dizziness;
• apathy, stress;
• heart pain;
• hypertension;
• insomnia;
• fatigue and more.

So, if you do not follow all the rules of the TCO base, the consequences can be extremely sad and irreversible. It is difficult to answer the question of how long or years it takes for the first symptoms to appear, since it all depends on the microwave model, manufacturer, and human condition.

Protection measures

According to TSO, the impact of a microwave depends on many nuances, most often it is:

• wavelength;
• duration of irradiation;
• use of specific protection;
• beam types;
• intensity and distance from the source;
• external and internal factors.

In accordance with the TSO, you can defend yourself in several ways, namely individual, general. Tso measures:

• change the direction of the rays;
• reduce the duration of exposure;
• remote control;
• indicator state;
• protective screening has been used for several years.

If it is not possible to follow TCO, it can be guaranteed that the condition will worsen in the future. TCO options are based on the functions of the oven - reflection as well as absorption capability. If no protective equipment is available, use special materials capable of reflecting adverse effects. Such materials include:

• multilayer packages;
• shungite;
• metallized mesh;
• overalls made of metallized fabric - an apron and a potholder, a cape equipped with goggles and a hood.

If you use this method, then there is no reason for excitement for many years.

Apples in the microwave

Everyone knows that baked fruits and vegetables are very nutritious, healthy, baked apples are no exception. Baked apples are the most popular and delicious dessert that is prepared not only in the oven, but also in the microwave. However, few people think that microwave-baked fruits can be harmful.

Baked apples contain many vitamins, nutrients, get a more tender and juicy structure. Baked fruits are not harmful, so it is important to choose the method of preparation. As it became known, baked apples in the microwave are not harmful, as they are not ionized.

In simple words, baked apples are a very tasty, valuable food that can be cooked in a microwave without harm to health. If you do not follow the rules of operation, neglect the indicator, then you can harm your condition. Baked apples are very easy to make as the microwave cuts down on the cooking time. The indicator on the display is responsible for all other functions, so it is important to keep an eye on it.

It is important! If an indicator fails, it cannot be repaired. The indicator is a special LED light bulb. That is why thanks to the indicator you can find out about the health of the device.

Answering the question whether the harm of microwaves is a myth or reality, we can say for sure that this is not a myth. By following the suggested recommendations, operating rules, you will protect yourself from negative impacts.

According to its purpose, protection can be collective, providing for measures for groups of personnel, and individual - for each specialist individually. Each of them is based on organizational and engineering measures.

Organizational protection measures are aimed at: choosing rational modes of equipment operation, limiting the place and time of personnel being in the zone of exposure to electromagnetic radiation (protection by “distance” and “time”), etc. Organizational measures for collective and individual protection are based on the same principles and in some cases belong to both groups. The difference is that the former are aimed at normalizing the electromagnetic environment for entire teams, on large production areas, and the latter reduce radiation during the individual nature of work. Protection by "distance" implies the definition of sanitary protection zones, zones of inadmissible stay at the design stages. In these cases, to determine the degree of impact reduction in some spatial volume, special computational, graphic-analytical, and, at the operational stage, instrumental methods are used.

Protection by "time" provides for being in contact with radiation only when necessary with a clear regulation in time and space of the actions performed; work automation; reducing the time of adjustment work, etc. Depending on the influencing levels (instrumental and calculation methods of evaluation), the time of contact with them is determined in accordance with the current regulatory documents.

Organizational protection measures should also include a number of therapeutic and preventive measures. This is, first of all, a mandatory medical examination upon employment, subsequent periodic medical examinations, which makes it possible to identify early violations in the state of health of personnel, to remove them from work in case of pronounced changes in the state of health. In each specific case, the assessment of the risk to the health of workers should be based on the qualitative and quantitative characteristics of the factors. Significant from the standpoint of influence on the body is the nature of professional activity and work experience. An important role is played by the individual characteristics of the organism, its functional state.

Organizational measures for protection against electromagnetic radiation (EMR) should also include the use of visual warnings about the presence of a particular radiation, the presence of posters with a list of basic precautions, briefings, lectures on labor safety when working with sources of EMR and prevention of their adverse effects. An important role in the organization of protection is played by objective information about the levels of EMR intensities in the workplace and a clear idea of ​​their possible impact on the health of workers. It should be noted that in some cases, organizational measures are not applicable due to the limitation of work on time ( stress-free repairs) or their use is limited by the installation geometry, for example, the size of the clearances ( in electrical installations of high and extra high voltage I). In addition, organizational measures are not applicable in cases where the technological process does not allow this ( when working at height, working on contact network under induced and operating voltage). Engineering and technical protection measures are applied in cases where the effectiveness of organizational measures has been exhausted. Engineering and technical measures include: rational placement of equipment; the use of means that limit the flow of electromagnetic energy to the workplaces of personnel ( power absorbers, shielding, use of the minimum required generator power); designation and fencing of areas with an increased level of EMP. Collective protection in comparison with individual is preferable due to ease of maintenance and control over the effectiveness of protection. However, its implementation is often complicated by high cost, the complexity of protecting large spaces. It is impractical, for example, to use it when carrying out short-term work in fields with an intensity above the maximum permissible levels. These are repair work in emergency situations (work on the contact network under operating and induced voltage), adjustment and measurement in open radiation conditions, when passing through hazardous areas, etc. In such cases, it is advisable to use personal protective equipment. The tactics of applying methods of collective protection against electromagnetic radiation depends on the location of the source of exposure in relation to the production room: inside or outside. Personal protective equipment is designed to prevent exposure of the human body to EMR with levels exceeding the maximum allowable, when the use of other means is impossible or inappropriate. They can provide general protection, or protection of individual parts of the body (local protection). Generalized information about personal protective equipment against EMR is presented in Table 1.

Table 1. Special means of protection against the action of EMP

1. Protection against the action of electromagnetic radiation of radio frequency and microwave ranges

The organizational measures of collective protection against the action of electromagnetic radiation of radio frequency (EMR RF) and microwave (EMR microwave) ranges include:

• use of means of visual warning about the presence of EMR: posters, leaflets with a list of basic precautions; conducting lectures on labor safety when working with EMR sources and prevention of overexposure from their impact; reducing the impact of related production factors);
• development of an optimal mode of work and rest for the team with the organization of working time with a minimum possible contact in time with EMI);
• rational placement of irradiating and irradiated objects: increasing the distances between them, raising antennas or radiation patterns, etc.)

Engineering and technical measures of collective protection against the action of RF EMP and microwave EMP include the following (see below).

Picture 1

• therapeutic and preventive measures ( conducting a medical examination when hiring, periodic medical examinations and medical supervision of personnel, objective information about the level of intensities at the workplace and a clear idea of ​​their possible impact on the health of workers, briefing on safety rules when working in conditions of exposure to EMR);
• measures to protect "time" ( being in contact with EMP only when necessary with a clear regulation in time and space of the actions performed);
• measures to protect "distance" ( organization of the workplace in order to create conditions with minimal levels of EMR).

The use of power absorbers. The principle of absorption of electromagnetic energy underlies the use of power absorbers used as loads on generators instead of open radiators. Thus, the space is protected from the penetration of EMP into it. Power absorbers are segments of coaxial or waveguide lines partially filled with absorbing materials. The radiation energy is absorbed in the filler, being converted into heat. Aggregates can be: pure graphite (or mixed with cement, sand, rubber, ceramics, powdered iron), wood, water. Attenuators can also be used to lower the radiation power level in the path (or to open radiation).. According to the principle of action, they are divided into absorbing and limiting. Absorbing are pieces of coaxial or waveguide protection, in which parts with a radio-emitting coating are placed. Limit attenuators are segments of circular waveguides, the diameter of which is much less than the critical wavelength in the operating wavelength range of this attenuator. In this case, the radiation power passing through the attenuator decays according to an exponential law.

The organizational measures of individual protection against the action of RF EMR and microwave EMR include:

• Shielding. Shielding is generally understood as both the protection of an employee from the effects of external fields, and the localization of the radiation of any means, preventing the manifestation of these radiations in environment. In any case, the shielding efficiency is the degree of attenuation of the field components ( electrical or magnetic), defined as the ratio of the effective values ​​of the field strength at a given point in space in the absence and presence of a screen. Shielding of EMR RF and EMR microwave sources or workplaces is carried out using reflective or absorbing screens. The effectiveness of shielding devices is determined by the electrical and magnetic properties of the shield material, the design of the shield, its geometric dimensions and the radiation frequency. To reduce EMI RF and EMI microwave protective devices must be an electrically and magnetically closed shield.

Figure 2

To avoid the saturation effect, the screen is made multilayer, and it is desirable that each subsequent (with respect to the shielded radiation) layer has a higher initial value of magnetic permeability than the previous one, since the equivalent depth of penetration of the electromagnetic field into the thickness of the material is inversely proportional to the product of its magnetic permeability and conductivity.

Protection based on the principle of radio absorption is used to create analogues of free space with antenna loads; if it is impossible to use any other protective materials due to a possible violation of the technological process; when lining the joints of the inner surface of cabinets with generator and amplifying equipment that generates EMP; when laying gaps between those parts of waveguide structures that cannot be connected by welding or soldering. The radio absorbing materials used must meet the following requirements: maximum absorption of electromagnetic waves in a wide frequency range, minimal reflection, no harmful fumes, fire safety, small size and weight.

In terms of maximum absorption and minimum reflection, materials with a cellular structure, a pyramidal or spike-like surface have the best qualities. From the side not subject to irradiation, radio-absorbing materials are covered, as a rule, with radio-reflective ones, as a result of which the characteristics of the entire shielding structure are greatly improved. The criterion characterizing the protective properties of the radio-absorbing material is the power reflection coefficient.

Thus, special materials are used in absorbing screens to ensure the absorption of radiation of the appropriate wavelength. Depending on the radiated power and the relative position of the source and workplaces, the constructive solution of the screen may be different (closed chamber, shield, cover, curtain, etc.).

The second component of the shielding efficiency Eotr is due to the reflection of an electromagnetic wave at the free space-screen interface. A significantly greater shielding effect can be achieved by using not homogeneous, but multilayer screens of the same total thickness. This is explained by the presence of several interfaces in multilayer screens, on each of which an electromagnetic wave is reflected due to the difference in the wave impedances of the layers. The efficiency of a multilayer screen depends not only on the number of layers, but also on the order in which they are interleaved. The most effective screens are made of combinations of magnetic and non-magnetic layers, and it is preferable to make the outer layer with respect to the field radiation source from a material with magnetic properties.

Calculation of shielding efficiency by two-layer shields made of different materials shows that the combination of copper and steel layers is the most appropriate in the frequency range of 10 kHz - 100 MHz. In this case, the thickness of the magnetic layer should be greater than that of the non-magnetic layer (steel - 82% of the total thickness, copper - 18%). An additional increase in the thickness of the shield by one layer leads to a not very noticeable increase in the shielding efficiency. When designing electromagnetic shields in the general case, it must be borne in mind that on a relatively low frequencies the most difficult is to provide effective shielding of the magnetic component of the field, while the shielding of the electrical component is not particularly difficult even when using perforated or mesh screens. When manufacturing a screen in the form of a closed chamber, the inputs of waveguides, coaxial feeders, water, air, outputs of control knobs and adjustment elements should not violate the shielding properties of the chamber. Screening of viewing windows, dashboards is carried out using radio-o protective glass. To reduce the leakage of electromagnetic energy through the ventilation shutters, the latter are shielded with a metal mesh, or are made in the form of transcendental waveguides. Reduction of energy leakage from flange joints of waveguides is achieved by using "choke flanges", sealing joints with gaskets made of conductive (phosphor bronze, copper, aluminum, lead and other metals) and absorbing materials, and additional shielding.

Screens are made using the following materials:

metal materials. Metallic materials are selected from the conditions:

• achieving a given value of the weakening of the electromagnetic field and its components in the operating frequency range with appropriate restrictions on the size of the screens and its effect on the shielded object;
• corrosion resistance and mechanical strength;
• manufacturability of the screen design and obtaining the required configuration and high-dimensional characteristics.

Almost all currently used sheet materials (steel, copper, aluminum, brass) satisfy the first requirement, since with their appropriate thickness they provide a sufficiently high shielding efficiency. But in different operating frequency ranges with the same screen thickness, the shielding efficiency of magnetic and magnetic materials will be different. That is, while the screen works as magnetostatic, the efficiency of magnetic materials is much higher than non-magnetic ones. In the electromagnetic mode, in the frequency band where the shielding efficiency due to reflection is greater than the absorption efficiency, non-magnetic materials, which are highly conductive compared to magnetic ones, provide higher efficiency.

However, in real screens, these properties of magnetic and nonmagnetic materials are weakly manifested. Due to economic and structural considerations, preference is given to steel construction screens. The advantages of steel are lost when shielding current-carrying elements that are critical to the losses introduced into them (i.e., the use of steel shields is limited due to the large losses introduced by them). The use of steel for screens is also due to the fact that when mounting such a screen, welding can be widely used.

The thickness of the steel is selected based on the type and purpose of the structure, the conditions for its installation and the possibility of continuous welds. When welding on alternating current thickness is taken approximately 1.5-2 mm, on DC- about 1 mm, with gas welding - 0.8 mm.

The disadvantages of sheet metal screens include:

• high cost (bronze, silver, etc.);
• significant weight and dimensions;
• the complexity of the spatial solution of the structure;
• low efficiency of the metal itself, realized only by 10-20% due to the imperfection of the design.

Figure 3

Mesh materials. Mesh materials have found wide application in shielding due to their advantages over sheet materials. Metal meshes are much lighter than sheet materials, easier to manufacture, easy to assemble and operate, provide sufficient air exchange, are translucent, and have sufficient shielding efficiency over the entire radio frequency range. However, the meshes do not have high mechanical strength, they quickly lose their shielding efficiency due to aging (this loss occurs due to the corrosion of the meshes, so the meshes are specially coated with an anti-corrosion varnish). The shielding properties of metal meshes are manifested mainly as a result of the reflection of an electromagnetic wave from their surface. The grid parameters that determine its shielding properties are the grid spacing S equal to the distance between adjacent wire centers, the wire radius r, and the specific conductivity of the grid material.

foil materials. These include electrically thin materials with a thickness of 0.01 - 0.05 mm. The range of foil materials includes mainly diamagnetic materials - aluminum, brass, zinc. The industry does not produce steel foil materials.

Installation of foil screens is not difficult, because the foil is fastened to the base of the screen by riveting. The choice of adhesive should be made taking into account the operating conditions of the screen, which include temperature, humidity, vibration loads, etc. The choice of material thickness should be made taking into account the possibility of resonance phenomena. There are graphs for various materials, where it is indicated for the lowest resonant frequency screen thickness vs. frequency for different screening efficiencies.

The shielding efficiency with foil materials is quite high for the electromagnetic field and the electrical component. Such materials weaken the magnetic component relatively little and the less, the longer the wavelength. Conductive paints. The use of conductive paints for electromagnetic shielding is a very promising direction, because their use eliminates the need for complex and time-consuming work on the installation of the screen, connecting its sheets and elements to each other. Conductive paints are created on the basis of a dielectric film-forming material with the addition of conductive components, a plasticizer and a hardener. Colloidal silver, graphite, carbon black, metal oxides, powdered copper, and aluminum are used as conductive pigments. Conductive paint is usually stable and retains its initial properties under conditions of sudden climatic changes and mechanical stress. The effectiveness of shielding with conductive paints is determined in the same way as for electrically thin materials.

Metallization of surfaces. The plating of various materials for electromagnetic shielding is becoming more widespread due to the high productivity and versatility of coating methods. Of the existing coating methods, the most convenient method is the spraying of molten metal with a jet of compressed air. It is possible to apply a metal layer on any surface of materials such as thick paper, cardboard, fabric, wood, textolite, plastic, dry plaster, cemented surfaces, etc.

Metallization layers can be of various thicknesses. The thickness of the layer does not depend on the type of metal - coating, but depends on the properties of the substrate (base). The amount of the applied metal layer must correspond to the physicochemical properties of the substrate material, its strength and deformation characteristics. For example, for thick paper, the metal layer should be no more than 0.28 kg / m2, for fabric - up to 0.3 kg / m2. For a rigid substrate, the amount of deposited metal is not significantly limited, since more significant limitations are caused by the high overall characteristics of the screen. The most common coating is zinc. This coating is technologically advanced, provides a relatively high shielding efficiency and sufficient mechanical strength for many screens. Aluminum coatings have an efficiency 20 dB higher than zinc coatings, but they are less technologically advanced.

It should be noted that, other things being equal, the shielding efficiency of a metallized layer is lower than that of a solid sheet of the same thickness. This is explained by the fact that the conductivity of the deposited layer is less than the conductivity of the starting material (metal). Surface metallization can be successfully used for shielding rooms and cabins, in the conditions of dividing radio electronic equipment (RES) into separate shielded compartments with a non-metallic common supporting structure, for individual devices mounted in plastic cases. Metal surfaces are also applied to glass surfaces. Glasses with conductive coatings are mainly used in viewing windows and search systems of RES, in shielded RES systems and chambers in order to provide light access to them. A closed screen made of glass with a conductive coating is also used when it is required to observe the processes taking place inside the screen. Currently, there is a range of glasses with conductive coatings that have a surface resistance of at least 6 ohms with a deterioration in transparency of no more than 20%. The shielding efficiency of such glasses is approximately 30 dB.

Tin oxide films are the most widely used, since they provide the greatest mechanical strength, are chemically stable, and adhere tightly to the glass surface (substrate).

Materials used for protection against microwave radiation. Such materials include the following (see below).

a) Special fabrics (type PT and article 4381). RT fabric is made of kapron threads twisted with flattened and silvered copper wire with a diameter of 35 ... 50 mm. The fabric of article 4381 has a thread with an enameled PEL-0.06 microwire. The number of metal threads can be 30x30, 20x20, 10x10 and 6x6 in 1 cm. Since the wire is insulated, the surface resistance of this fabric is high. Special suits for individual biological protection are usually made from such fabrics.

b) Radar absorbing materials (RPM). These materials are not classified as shielding materials, although some of them are produced on a metal base, which, with careful connection of its individual parts and elements, can serve as a screen. However, the installation of such screens is very complicated, so the screen is covered with an absorbing material inside in order to reduce the reflection of radio waves.

c) electrically conductive adhesives (EPC). It is advisable to use this adhesive instead of soldering, bolted connections where electromagnetic shielding is needed. Seam connection, fastening of contact systems and various elements of screens, filling gaps and small holes, installing a screen on a supporting structure - these and other operations can be successfully carried out using EPC with high shielding efficiency and reduced work.

The composition of EPA is an epoxy resin filled with fine powders (iron, cobalt, nickel). The adhesive cures very quickly (5 minutes) if the process is carried out with high frequency currents.

Construction Materials. Certain protective properties, evaluated by the degree of through attenuation, are possessed by building materials and structures made of them. For structures made of various shielding materials, the degree of end-to-end attenuation is estimated only according to the results of the instrumental method.

• Afforestation. Use as a protection for forest plantations is also based on radio absorption. The protective effect of forest plantations is most pronounced when they are in close proximity to the protected object. In this case, only the degree of end-to-end attenuation is taken into account. With a large length of the object in depth and a dense protective strip of tall trees, it is necessary to take into account diffraction attenuation.
• Sector blocking of the radiation direction.

Use of radio absorbing volumes. When microwave and RF sources are found indoors, it is advisable to carry out protection in places where electromagnetic energy penetrates from shielding casings, improve methods of radio sealing of joints and joints, and use nozzles with a radio absorbing load. With external sources, various protective products made of radio-reflecting materials are used: metallized wallpaper, metallized curtains, window screens, and others. These protective agents are most effective in the microwave range; at lower frequencies, their use is limited by diffraction.

In some cases, special corridors with walls made of radio-reflecting materials (aluminum sheet, brass mesh, etc.) are used to protect against radiation from external sources. Evaluation of the effectiveness of the listed collective means of protection is carried out according to the degree of through and diffraction attenuation.

Engineering and technical measures for personal protection against the action of RF EMR and microwave EMR include:

• shielding of individual workplaces with radio-reflecting or radio-absorbing materials;
• individual means of total protection, complete with means of local protection ( suits, overalls complete with helmets, masks, shoe covers, gloves);
• personal means of local protection ( radioprotective gowns, gloves, helmets, shields, goggles, etc.).

Protective glasses. Spectacle lenses are made of special glass ( for example, coated with tin dioxide - TU 166-63), cut out in the form of ellipsoids with a semicircle size of 25x17 mm and inserted into a porous rubber frame with a metal mesh sewn into it.

Various materials can be used to make protective glass. It depends on the degree of their optical transparency and protective properties for certain EMP frequencies. The protective properties of glasses are evaluated by the degree of attenuation of the glass used. It should be borne in mind that protection glasses up to 10 dB can only be obtained at a radiation frequency of more than 3 GHz. At lower frequencies (less than 1 - 2 GHz) they are useless. Therefore, in the future, when developing PPE from EMP, eye protection, the face area should be total like a helmet with a translucent area at eye level, but with sufficient radioprotective property in a wide frequency range, including 1–2 GHz.

Protective masks. Protective masks are made of any translucent material with the inclusion of any radio-reflecting structures: metal sputtering, metal oxide films, coating of metallized meshes.

The shape and size of the mask are chosen so that the value of diffraction attenuation at eye level is not less than the attenuation of the protective material. In order to ensure breathing and heat exchange, perforations are made in the protective mask along its perimeter.

Protective helmets, aprons, jackets, shoe covers. To provide the necessary protection efficiency, helmets, aprons, jackets, shoe covers and other local protection elements are made taking into account all the requirements of through, diffraction attenuation. In practice, it must be borne in mind that the protective properties of materials from EMR and products made from them are not the same thing. This is due to the different radio frequency properties of protective products as a whole, the presence of joints of individual parts of structures. Inevitable is the appearance of resonant effects inherent in various irregularities on products, the dimensions of which are multiples of the wavelength of the acting EMP. It should be noted that if these effects are neglected, then the end-to-end attenuation of any material is always greater than its end-to-end attenuation in the structure. Although most measurement methods are designed only to determine the shielding properties of materials, they are also suitable for products in general.

2. Protection against electromagnetic radiation industrial frequency

Organizational measures of collective and individual protection against industrial frequency EMR (IF EMR) are of the same nature as for protection against RF EMR and microwave EMR, and are presented in clause 1 of these guidelines.

Common collective means of protection against the action of EMP FC are the following (see below).

• Shielding awnings. Shielding canopies are made of parallel conductors (diameter 3 - 5 mm, distance between them 20 cm) and are located at a height of 2.5 m above the footpaths.
• Shielding visors. Screening visors used as protection are made in the form of meshes of the same material with a mesh size of 5–10 cm.
• Screening barriers. For the passage of people, the passage of vehicles, agricultural machinery under high-voltage power lines, devices related to collective protective equipment are organized. In particular, these include reducing the distances between supports, the use of shielding cables, canopies stretched on grounded supports. In some cases, screens are installed at 400 and 500 kV installations at a distance of 4.5 m and 750 kV at a distance of 6 m to current-carrying parts.

In all cases, shielding devices must be grounded with a grounding device resistance of 10 ohms. * neutralizers. These devices are designed to compensate for electric fields of industrial frequency 50 Hz in the area of ​​technological and office equipment, computer equipment and household electrical appliances, reducing the harmful effects of fields on the human body. If the power consumers will be supplied not directly from the mains socket, but through this neutralizer, then the electric field in this case is localized in the space between the mains socket and the neutralizer. In the area where the equipment is located (as well as in the entire room), the electric field is reduced by 15–20 times. As engineering and technical measures of individual protection against the action of EMR FC, personal protective equipment for personnel under the influence of electrical radiation of industrial frequency with a voltage above the maximum permissible levels (MPL) is widely used. These include shielding clothing made from ordinary woven fiber with a metallized mesh (Table 1). In the manufacture of it, you can also use the so-called metallized fabric, which is an ordinary cotton fabric coated with a layer of metal or electrically conductive paint. It is also promising to use a fabric for screening clothing made of a conductive polymer, the electrical conductivity of which can increase with increasing tension. In addition to a suit or overalls, a set of clothing includes a shielding headgear, special shoes, gloves or mittens (Table 1). When using a set of protective clothing, all its elements must be securely connected by a conductor and grounded through conductive shoes or individual grounding. Personal protective equipment against EMP FC also includes individual removable screens made of mesh or metallized glass.

3. Protection against magnetic fields

Protective measures against the effects of magnetic fields (MF) mainly include shielding and "time" protection. Screens must be closed and made of soft magnetic materials. In a number of cases, it is sufficient to remove the operating MF from the zone of influence, since with the removal of the source of constant and variable MF, their values ​​rapidly decrease.

As means of individual protection against the action of magnetic fields, various remote controls, wooden pincers and other manipulators of the remote principle of operation can be used. In some cases, various blocking devices can be used to prevent personnel from being in magnetic fields with an induction above the remote control.

4. Protection against electromagnetic radiation of personal electronic computers

Methods for reducing the levels of electromagnetic radiation from personal electronic computers (EMP PCs) that affect a person can be divided into the following main groups (see below).

Figure 4

• Use of low-emitting video display terminals (VDTs). Since the source high voltage display with a cathode ray tube (CRT) - a horizontal transformer - is placed in the rear or side of the VDT, then it is necessary to use VDTs shielded from these sides by a metal casing. The monitor housing can act as a shielding casing, it is possible to use molding materials consisting of polymer resins, such as polypropylene, etc., filled with aluminum flakes, brass fibers and other metal fillers. EMR from the surface and through the screen surface of the cathode ray tube is shielded using a conductive coating applied to the inner or outer surface of the safety glass; or with the help of an additional protective filter, which is located in front of the screen.

It should be noted that liquid crystal (LCD) monitors do not have electrical circuits high voltage. Consequently, the levels of EMR, compared to VDTs with CRTs, are significantly lower.

• Application of external protective filters. Installing a protective filter on a CRT only reduces the level of EMP for a person sitting in front of the screen by only 2-4 times, reducing the electrical component of the EMP of the PC in the immediate vicinity of the screen, and not reducing at all, and maybe even increasing the intensity of the field away from the screen along the CRT axis by distances of more than 1 - 1.5 m. Therefore, it is more efficient to use filter designs with additional screening of the sides of the displays.

If the EMI from the monitor meets the requirements of international standards, then there is no need to purchase an EMI filter.

• Rational, from the point of view of the impact of EMR PC, the location of jobs. When considering the issue of locating the workplaces of PC operators in a room, it must be taken into account that in this case, the operator may be adversely affected not only by the computer he works on, but also by other computers located in this room. To exclude such influence, the following rules should be followed.

1. VDTs should, if possible, be placed in one row at a distance of more than one meter from the walls.

Figure 5

2. Workplaces of operators should be at least 1.2 meters apart. It is also allowed to place a VDT in the form of a "chamomile". However, it should be borne in mind that whatever the location of the computers in the working room, the rear wall of the computer should not be directed towards other workplaces. If this cannot be achieved with the help of a rational layout of the room, then in the design of the desktop it is necessary to provide for the possibility of mounting an electromagnetic shield from the side to which the back of the VDT is facing.

5. Protection against pulsed electromagnetic fields

In order to prevent the adverse impact of PEMF on the health status of personnel of radio engineering facilities (RTO), a set of measures is used, including organizational and engineering measures to reduce levels of PEMF at workplaces, as well as the use of collective and individual protective equipment.

Figure 6

Organizational activities include:

• removal of the workplace to the maximum possible distance from the source of PEMF;
• use of the minimum radiation intensity of the PEMF source necessary for solving the tasks;
• organization of a warning system about the operation of the PEMF source.

Along the perimeter of the RTO, PEMF are equipped with means of visual warning of the presence of PEMF. During the operation of PEMF sources, sound and (or) light signaling (alert) is organized.

The list of engineering activities includes:

• organization of remote control of equipment;
• grounding of metal pipes for heating, water supply, etc., as well as ventilation devices;
• shielding of individual units or all radiating equipment;
• strengthening the shielding properties of enclosing structures by coating the walls, floors and ceilings of the rooms in which PEMF sources are located with radio-absorbing materials;
• workplace screening.

Personal protective equipment against PEMF includes protective clothing (overalls and suits with hoods made of special electrically conductive radio-reflective or radio-absorbing fabric).

6. Protection against laser radiation

The means of protection against laser radiation are protective devices and safety signs. Protective devices and signs prohibit the presence of people in the danger zone.

Separate, specially equipped rooms are provided for the installation of lasers. The installation is placed so that the laser beam is directed to the main fire-resistant wall. This wall, as well as all surfaces in the room, should be coated or painted with a low reflectivity. Surfaces and parts of the equipment should not have a gloss that reflects the rays falling on them. Lighting in the room is provided with a high level of illumination so that the pupil of the eye has a minimum dilation. Automation and remote control of the installation are essential.

Personal protective equipment are: safety glasses with light filters, protective shields, gown and gloves.

Figure 7

7. UV protection

Figure 8

To protect against excess ultraviolet radiation (UVR), various screens are used that reflect, absorb or scatter rays. When arranging rooms, it must be taken into account that the reflectivity of various finishing materials different for UV than for visible light. Polished aluminum and honey white reflect well, while zinc and titanium oxides, oil-based paints do not.

In production, personal protective equipment is widely used. These include

• special clothing made from fabrics that are the least transparent to UV radiation (for example, poplin).
• eye and face protection. In production conditions, glasses or shields with light filters are used. Full protection against UV radiation of all wavelengths is provided by a 2 mm thick flint eye (glass containing lead oxide).
• dermatological personal skin protection products: protective creams with a protective factor that absorbs ultraviolet radiation of groups A, B, C, at least 18 units.