The microclimate in industrial premises is the permissible temperature standards. lighting requirements. Impact on a person

Hygienic standards for the parameters of the microclimate in the working area are given in GOST 12.1.005 - 76. The working area is considered to be a space up to 2 m high above the floor or platform on which the workplaces are located. A permanent job is considered to be one where the worker spends more than half of his working time or more than 2 hours continuously. If people work in different places working area, then you consider it all a permanent workplace.
The microclimate in the working area is determined by the combinations of temperature, humidity and air velocity acting on the human body, as well as the temperature of the surrounding surfaces. High humidity makes it difficult for the body to transfer heat through evaporation during high temperature air and contributes to overheating, and at low temperatures, on the contrary, enhances heat transfer, contributing to hypothermia. The optimal parameters of the microclimate are those that, with prolonged and systematic exposure to a person, ensure the preservation of normal functional and thermal state body without tension of thermoregulatory reactions, which creates a feeling of thermal comfort and serves as a prerequisite for high performance. maintenance optimal microclimate is possible only if the enterprise is equipped with microclimate conditioning units. In other cases, acceptable microclimatic conditions should be provided, i.e. such, in which, although there may be tensions in the body's thermoregulation, they do not go beyond the limits of its physiological adaptive capabilities. In this case, there are no violations of the state of health, but there may be a deterioration in well-being and a decrease in working capacity.
Hygiene standards depend on the category of work according to the degree of physical activity, as well as on the warm or cold period of the year and on the excess of sensible heat entering the equipment room, heated materials, heating appliances, people and sunlight, i.e. from the difference between sensible heat and heat losses when calculating the parameters of outdoor air, taking into account all measures to reduce heat losses. Excess heat is considered insignificant if it is not more than 23 J / (m3 x s), and if more, then the room belongs to the hot shop.
For example, for light work in the warm season optimum temperature equal to 22 ... 25 ° С, and the permissible (with significant excesses of sensible heat) is 5 ° С higher average temperature outside air at 13:00 of the hottest month, but not higher than 28 °C. Relative humidity is up to 55%. Air velocity 0.2...0.5 m/s ( optimal speed 0.2 m/s). In the cold period of the year at the same works, the optimum temperature is 20 ... 23 ° C, the permissible temperature is 19 ... 25 ° C. In some cases, certain deviations from the norms are allowed. The recording device-thermograph type M-1B measures the air temperature, and the humidity is measured with a psychrometer.

Rice. 26. Psychrometers:
a - Assman; b - Augusta; 1 - dry thermometer; 2 - fan head; 3 - wet thermometer; 4 - air channel; 5 - moistened tissue
The psychrometer (fig. 26) consists of dry and wet thermometers. Relative humidity is determined from tables depending on the difference in thermometer readings. For the same purposes, recording devices-hygrographs of the M-2I type, hot-wire anemometers of the EA-2M type, etc. are used.
Anemometer measures the speed of air flow: vane (Fig. 27, a) - from 0.5 to 10 m / s, cup (Fig. 27, b) - from 1 to 20 m / s. The vane anemometer has a light wheel with blades mounted at an angle on an axis, which is connected by a worm gear to the mechanism for rotating the arrows. The axis of the wheel is parallel to the air flow. The air speed is determined according to the schedule (located in the instrument passport) depending on the ratio of the readings on the anemometer and on the stopwatch turned on simultaneously with it.

Rice. 27. Anemometers:
a - winged; b - cup; 1 - wing; 2 - handle; 3 - revolution counter; 4 - cup
A catathermometer determines low air velocities (0.1 ... 1.5 m / s). It consists of an alcohol thermometer with a cylindrical or spherical reservoir at the bottom and has a cylindrical capillary extension at the top. For a catathermometer with a cylindrical reservoir, the scale is graduated from 35 to 38 °C. The tank is heated in water at a temperature of about 70 ° C until the alcohol, having passed the capillary, fills half of the upper expansion. Then the catathermometer is wiped dry and hung at the examined point of the room. The stopwatch determines the time during which the readings of the catathermometer decrease from 38 to 35 ° C as a result of cooling with an air flow, and then the air velocity is calculated according to the formula given in the device passport, taking into account the constant indicated there - the “device factor”.
An actinometer determines the intensity of thermal radiation. One of his designs is a slightly curved plate of constantan, covered with platinum black and reinforced on a base of material "invar", which has a negligible coefficient of thermal expansion. Under the influence of thermal radiation, the plate bends and the arrow of the device associated with it deviates.
Heating is provided in domestic and industrial premises where people are constantly. The heating system is chosen depending on the type of room and the presence of flammable gases, vapors, dust in it. For example, in their absence, steam, air (calorific) or water systems heating. With a floor area of ​​up to 500 m2, it is allowed stove heating. Cabins of cars, tractors and mobile agricultural machines most often have air heating: the air is heated from the engine cooling radiator. However, electrical heating is also possible.
When performing work in adverse microclimatic conditions, for example, outdoors in frosty weather, in addition to issuing appropriate clothing and footwear, it is necessary to organize work in such a way that it is possible to periodically warm the workers. To do this, it is necessary to provide stationary or mobile rooms with a temperature of at least 25 ° C and with dryers.

Heat, poor lighting and noise not only cause discomfort, but also affect safety, health and work efficiency. Although we feel, see and hear all these conditions, we often try not to notice them.”

Working conditions affect productivity

Ambient temperature, quantity and quality of lighting and noise levels are common factors in the working conditions of any workplace. These conditions can affect the safety and health of workers in factory settings where mechanization and automation have brought change. These factors, being redundant or inappropriate, can greatly affect the performance of the production task and its effectiveness.

All this affects the danger and health. For example, heat, humidity make the worker more fatigued and increase potential health hazards, besides, with noise it is impossible to hear warning signals or they can be misunderstood, and, eventually, noise leads to permanent hearing loss.

Technology to control temperature, provide adequate lighting and reduce noise is constantly evolving, creating efficient workflows to protect workers from health hazards. We must identify existing working conditions and try to change them by finding practical solutions.

In this chapter, we will discuss:

working area climate

thermal stress

methods of protection

· effects

lighting

exposure to noise

Noise control methods

Hearing protection.

Working area climate

Climate can be defined as the atmospheric conditions that surround us. It can be general terms and Conditions in a geographical area or, in a narrower sense, the local atmospheric conditions at a specific workplace. Often the climate of the work area (also called the microclimate) is determined by the overall climate.

During the hot season, people feel uncomfortable and labor productivity drops. By applying new technology and living standards, it is sometimes possible to achieve some degree of climate control in the place where we live and work. However, in the workplace or outdoors, we are often exposed to unbearable heat and therefore measures must be taken to protect against harmful effects.

It is possible to alleviate the effects of heat with the help of air conditioners, but this is an expensive undertaking and is not applicable everywhere. It is also important to ensure sufficient accumulation of fresh air.

body heat exchange

As a result of performing physical work, our body releases heat. To maintain normal body temperature, the body must get rid of excess heat. The body's heat exchange must be observed.

Heat exchange is understood as the usual balance between the received and given heat.

There are three main sources of heat:

air temperature, air velocity and humidity

radiation from the sun, machines and processes

muscle work.

In addition, there are three ways to release heat:

Convection (transfer of heat from the body to the environment), the stronger the wind, the higher the heat loss. Conversely, we absorb heat when the temperature of the surrounding air is higher than body temperature,

radiation (when the body gives off heat to cooler surrounding objects). But if the body is located near heated surfaces, then it absorbs heat. This happens when a person is in the sun, near a stove, a heated container, etc.,

Evaporation (during sweating, water evaporates from the surface of the skin and removes excess heat). Naturally, this type of heat loss through evaporation is easier to carry out in the presence of wind and more difficult in high humidity.

Thus, in a hot climate, the body can absorb heat in various ways, but the only way to effectively get rid of excess heat is through evaporation.

In order for the body to cope with the task of heat balance, these factors must not exceed certain limits. The range can vary from person to person, it can change depending on the time of year, clothing, severity, work performed and culture. However, all people accept the comfort zone, approximately 20 to 25 degrees Celsius at relative humidity from 30% to 70% if the physical activity is weak and there is no heat source nearby.

As physical activity increases, a cooler air temperature is required to maintain a comfortable state. Since during hard physical work the body generates heat with its muscular energy, a feeling of comfort is achieved at temperatures below 20 degrees Celsius.

An increase in wind speed can serve as a comfort factor if the ambient temperature is at or above the highest limit of the comfort zone. Movement speed 0.1-0.3 m/sec. favorable for creating a comfort zone when performing work related to light physical labor.

When the local climate does not allow the body to get rid of excess heat and reach normal temperature, a person experiences real discomfort. As a result, performance drops sharply. In extreme cases, you can reach complete exhaustion and loss of health.

Remember!

The body has the ability to reach its normal temperature by getting rid of excess heat. Outside the comfort zone, this ability to regulate heat balance is lost. The discomfort you feel in a hot zone is an important warning sign.

Thermal stress measurement

The degree of thermal stress can be measured by measuring the hot zone, or by measuring the state of the body exposed to this zone.

Measurement of working conditions

There are four main parameters that affect the degree of thermal stress:

· air temperature

relative humidity

temperature measured with a spherical thermometer (radiation temperature)

air speed.

To measure these parameters, the following instruments are required:

· Thermometer (glass thermometer) is used to measure the air temperature in the shade. The air temperature can vary from minus to approximately +50 degrees Celsius.

· Wet bulb thermometer is used to measure humidity using a glass thermometer. The lower part or flask of the thermometer is wrapped with gauze, the end of the gauze (and not the flask itself) is placed in a jar of water. If the air is dry, the water from the gauze will evaporate quickly and the temperature will drop. If the humidity is high, the water will evaporate slowly and the dry bulb and wet bulb temperatures will differ slightly. With the help of the difference between the two temperature readings in the table, you can determine the percentage value of relative humidity. Relative humidity ranges from 0% to 100%.

· The spherical thermometer is used to measure the radiation temperature, which can differ significantly from the air temperature. The thermometer bulb is placed in the middle of a hollow black copper sphere 15 cm in diameter. The black sphere absorbs radiation and warms the air inside it.

· The anemometer determines the wind speed. As an alternative, you can use a Kata thermometer, which has only two marks. It is placed in warm water and kept there until the mercury rises to the upper mark. Then it is wiped dry and placed in the air. A stopwatch measures the time it takes for the mercury to fall from the top to the bottom. From the attached table, you can determine the wind speed, based on the time required for the thermometer to cool.

AIR TEMPERATURE is measured with a conventional thermometer. The tip of the thermometer is protected from direct radiation by a polished cylinder with holes at both ends. The readings are taken after about 5 minutes. AIR HUMIDITY can be measured with dry and wet hydrometers. Other instruments can be used, such as a thermohydrograph that records humidity over a longer period of time. RADIATION TEMPERATURE is measured using a spherical thermometer. Indicators are taken after 20-30 minutes. AIR VELOCITY can also be measured with a device specially designed for very low air velocity (0.2 m/s), which is often observed in work areas.

In some cases, all four of these measurements can be combined into a single unified measure of thermal stress.

It is important to ensure that the air temperature does not deviate significantly from the temperature of the comfort zone and that the radiation temperature is the lowest in the areas where the work is done, especially at high relative humidity. It should be noted that a small breeze helps to get rid of the state of discomfort.

Measurements of the state of the human body

If the worker is in a state of thermal stress, the body temperature rises. The body responds to this with various defense mechanisms to keep body temperature constant. The temperature is rising skin(heartbeat quickens, breathing becomes deeper), and the person begins to sweat. Thus, body temperature (measured by putting a thermometer in the mouth) testifies to all the protective changes taking place in the body. However, body temperature should not change by more than 1 degree Celsius.

Based on studies of heat stress in industry, it was found that the level of sweating can serve as an indicator of body stress. The amount of sweat produced during working hours is measured by the weight loss calculation, taking into account the weight of food and drink consumed, fumes and any changes in clothing. Hot shop weight loss after work shift can be up to several kilograms.

Sweat contains salt. With excessive sweating, the body loses a large number of salt. In extreme cases, muscle spasms occur due to a lack of salt.

Losses of water and salt during sweating must be restored. Unfortunately, when you feel thirsty, it is not always enough to drink water. A healthy young man in a very hot workshop can lose up to 1 liter of sweat per hour. But it can usually withstand a loss of up to 4 liters during an 8-hour work shift, provided that it replaces the loss of water and salt. To do this, you need to drink clean water or fruit juices. It is good to add salt to food and eat foods that contain natural salt or other minerals.

If sweating is not made up for by drinking, then the body excretes very little urine, and the urine itself is thick and dark in color, and this is very unhealthy.

Sweating is necessary. Unnecessarily, the body does not sweat. It is dangerous to reduce perspiration by reducing water intake.

There are two medical consequences of heat disturbance: heat exhaustion and heat stroke.

· Heat exhaustion occurs when a person feels dizzy and faint, which is due to the lack of blood flowing to the brain. The blood pressure drops. You need to lie down in a cool place so that the blood flows to the head.

· Heatstroke occurs when a person's skin is very hot and dry, which is caused by an abnormal sweating mechanism. There is a rapid increase in body temperature up to 40 degrees Celsius, which is often accompanied by a reduction in sweating. In this case, you should immediately call a doctor or provide medical assistance. While waiting for help, it is vital to cool the body with wet sponges.

Remember!

· Sweating is necessary. The body does not sweat unnecessarily, since the loss of water and salt through perspiration is not indifferent to health, one should try to create such working conditions in which workers do not sweat much. It is dangerous to reduce sweating by reducing fluid intake.

Acclimatization occurs when a person lives and works in a hot climate. This means that a person has adapted and is accustomed to a hot climate. In fully acclimatized workers, heart rate and body temperature are less responsive to working in a hot environment. They may have blood circulation closer to the surface of the skin.

However, there are limits to the adaptability of the organism. Even in relation to a fully acclimatized person, thermal stress should be reduced to a minimum.

Questions:

· Is the local climate in a good zone?

What are the signs that a worker is suffering from severe heat pressure?

What factors increase heat pressure?

How does the body protect itself from heat?

· Is cool drinking water provided at your workplace?

Thermal protection

How to do workplace cooler

There are several ways to cool the atmosphere in the workplace. The main idea is to protect the workplace from the penetration of external heat and increase ventilation, this is traditionally done in dwellings located in tropical climates. Do not forget:

Keep the evening cool for as long as possible by airing the room in the evening, taking into account the layout of the building. In places far from the sea, it is usually much cooler in the evenings and in the morning than in the daytime.

open windows and doors wider to increase natural ventilation,

avoid floor coverings that retain heat, such as soil, wood, carpets, try to increase air circulation under the floor,

The structure of the roof must be such that heat can escape to the outside. Of particular importance is the material from which the roof is made, and the design of the roof itself. good ventilation under the roof significantly reduces the heat in the room. In order to avoid direct radiation coming from the roof, the material of the roof or ceiling must be changed. A roof painted in light colors will reflect the heat coming from the sun and sky,

· lengthen cornices or other awnings so that the walls are in the shade for as long as possible. Walls, especially those on the sunny side, should be painted in light colors. For wall material, do not use metal or other thin surfaces that are easily heated by the sun,

Use a light range of colors to paint the walls inside the room. Light surfaces radiate less heat than dark ones. Light colors also psychologically create a feeling of coolness.

Ceilings must be high. High ceilings are better than low ceilings, install ventilation devices. Helps artificial ventilation to improve airflow: remove hot air and blow in cool air.

Use electric fans to circulate air.

Machinery and production processes that generate heat

Thermal stress is greatly increased by the use of equipment and manufacturing processes that generate heat. The operator must be protected from heat.

This can be done subject to the following rules:

· Equipment and processes that generate heat must be located outside or in contact with the outside of the building so that heat can be released to the atmosphere.

· hot surfaces should be insulated by materials such as foam or polyester over the metal surface. This retains heat, saves fuel consumption and reduces the possibility of accidents associated with contact between a hot surface and a body,

Barriers are installed between the hot zone and the workplace. Shields with a reflective surface made of aluminum, | water curtains, screens made of panels sheathed in wood or fabric, can serve as effective heat-protective barriers,

heat-protective aprons and other clothing, such as vests with aluminum coated help protect against heat. However, this approach is not suitable for long-term heavy workloads, because the high degree of insulation of the clothing prevents heat from being removed through evaporation.

It is rarely possible to reduce strong heat radiation with an exhaust fan. the only effective way can become a partition between the hot zone and the workplace, so that hot air flows are not directed at the workers.

Remember!

· It is no coincidence that some traditional dwellings in shady forests attract with their coolness. They use different methods to get rid of unnecessary heat radiation and increase ventilation. We should act as wisely as our ancestors did. Use in the best possible way ventilation openings, baffles, protective screens and natural ventilation.

Air conditioning

Air conditioning allows you to adjust the indoor climate to the comfort and health of people. Typically, an air conditioning system simultaneously controls temperature, humidity, and air purity. Air conditioning is a very expensive piece of equipment, especially in factories, but it can sometimes be a worthwhile investment. It is well known that air conditioning improves productivity, helps reduce accidents, reduces absenteeism due to illness, and improves human relationships.

The air conditioning system must:

be of a type to meet the requirements of the premises,

take into account the concentration of gases, vapors and dust in a given room,

adjust the functions of the system in accordance with the convenience of people working in the room, and not depending on the readings of a thermometer,

Avoid hypothermia and drafts

· provide good maintenance of air conditioning equipment, including its humidity control elements.

What you need to do to prevent overheating of the body

In addition to these technical measures, it is necessary to know how to prevent overheating. Thermal energy comes from within the body. There are several ways to reduce heat generation and make it easier to release. Try:

Avoid unnecessary fast movements

think over how to do physical work with the least effort, trying to be less in the hot zone,

Avoid direct sunlight

sit or stand where there is a slight breeze from open doors, windows or fans,

Avoid enclosed spaces where air circulation is limited. If you work sitting, then use a seat that allows air to pass through,

· Keep away from heat sources such as hot liquids, equipment and fire. Where possible, install barriers,

do not wear tight clothing or clothing that prevents evaporation through perspiration,

Drink soft drinks regularly

Choose cool places to relax.

When working in a hot zone, it is very important to improve the working and living conditions of the workers. Heat exposure combined with exercise tends to be cumulative. It is extremely important to properly organize working hours. Do not forget:

· avoid long periods of work in the hot zone, where working conditions are particularly stressful,

take breaks from work, especially when performing moderate to heavy physical work performed in a hot, humid climate or with radiant heat, it is recommended to take 50% of the working time or even more to rest to prevent an increase in body temperature. Shorter run time does not necessarily mean lower performance,

organize a cool place to rest,

Ensure sufficient cold drinking water near the workplace. Liquids should be drunk in small quantities, but often,

Provide an opportunity to take a shower or clean work clothes.

Remember!

The heat released by the body during physical work is added to the heat coming from the environment. Many people doing heavy physical work in front of stoves or other hot areas have body temperatures as high as 39°C. In order to cope with a high temperature, you need to reduce physical activity and rest more often.

Questions:

· What are the main technical measures against heat?

Cold protection

People who work in cool rooms or outdoors in winter, and people who work with refrigerated or frozen food, are exposed to the cold. A large temperature difference between a cool room and the outside environment is inconvenient and may be harmful to health. Staying in the cold for a short period of time can also have serious consequences, especially if the temperature drops below 10°C. Heat transfer by the body occurs with unpleasant sensations and quickly affects labor productivity. Prolonged exposure to cold or very cold outdoor conditions can be life-threatening due to a sudden drop in body temperature.

Exposure to cold can be reduced by wearing thick, warm clothing and gloves.

In cold climates, heat loss from the body is increased by air movement. Indeed, the best protection against cold can be to reduce the air flow over the surface of the body, thus reducing heat transfer through convection and evaporation. This can be done with both clothing and wind protection.

Working in a cold zone causes some problems, for example:

· First, the hands and feet freeze, then the arms, legs, and finally the whole body.

Workers have a loss of coordination of movements, which reduces the speed and quality of work, as well as work safety. In addition to feeling awkward, the ability to concentrate decreases. The condition caused by discomfort affects safety.

Bulky clothing is dangerous. It makes it difficult to move, in addition, parts of clothing can get into working parts of machines. The same applies to thick gloves.

Hands cool faster when handling metals and liquids.

· Exposure to cold, especially at temperatures below 0°C, can cause frostbite of the fingers, toes, nose and ears. This is disturbing, as well as painful and dangerous.

Wet cold is more unpleasant than dry. This is mainly due to the fact that moisture reduces the insulating properties of all types of clothing except wool.

Remember!

· Cold has a significant impact on safety, even if the worker is exposed to cold for a short period of time.

WORKING AT HIGH TEMPERATURE Use thick, rough gloves, such as leather. Inner gloves (or lining) must be of heat-resistant material. Some glove designs can withstand temperatures up to 400°C. OPERATION IN HUMIDITY AND COLD Use short gloves with a knitted lining and a waterproof top. LEATHER GLOVES They are used to perform work related to the movement of heavy objects in a dry environment. If the most vulnerable parts of the gloves are reinforced with an additional layer of material, they will last longer. WORKING WITH CHEMICALS Use long rubber gloves made of chloroprene with a knitted lining of moisture-absorbing fiber with long cuffs.

Heating doesn't cost as much as air conditioning, and well-designed clothing can provide protection from almost any climate. However, it is necessary to think carefully and take into account the following conditions:

· When choosing clothes, you need to take into account protection from moisture and wind. The body sweats at any temperature.

· Waterproof clothing prevents evaporation. In this case, it becomes wet from the inside. Appropriate clothing provides both moisture evaporation and protection from rain and wind.

Bulky clothing should be avoided as it makes movement difficult.

· When doing heavy work, overheating while wearing warm clothing can be a serious problem. Wear layered clothing (vest, shirt, pullover, windbreaker) so that you can gradually undress, or wear quilted clothing with zippers.

· Hands and feet are particularly sensitive to the effects of cold.

· Older people should be better protected from the cold than younger people.

· Equipment and production tasks should be designed to be less dangerous and easy to carry out (eg size and spacing of triggers, isolation of metal parts, elimination of sharp protrusions, etc.).

· It is very important to provide comfortable heated places for recreation.

Questions:

· Are there situations in your workplace where workers are exposed to cold? Are workers aware of the dangers associated with the cold?

· What specific safety precautions should be taken when working in the cold?

Lighting

The color of the iris determines the color of the eyes. The black hole in the middle of the iris is the pupil. The size of the pupil is determined by the intensity of the light flux falling on it.

EYES NEED ENOUGH LIGHTING.

We often forget how important lighting is both at home and at work. The eye has the ability to adapt to a wide range of light conditions, but insufficient room lighting makes work difficult and can lead to accidents. Poor lighting also causes various eye diseases and blurred vision.

When performing most work, it is necessary to clearly see the materials, products, equipment. If we cannot see the subject well, it causes fatigue, overwork and headaches.

The eye can be compared to a camera. When rays of light enter the eye, they penetrate the inside of the eyeball, which consists of the cornea, the lens and the intraocular fluid located between them. The region of the eyeball behind the lens is filled with transparent aqueous humor, through which the rays pass to obtain an image on the retina, the concave part of the eye's chamber. The retina performs the same function as the photosensitive film in a camera. Appropriate lighting is needed for the following reasons:

· Focusing: the eyes are unable to focus on both distant and nearby objects at the same time. When you have to change the focus on objects located at a distance from each other, the eyes quickly get tired. This happens in jobs such as quality control or assembly line work. In such cases working room should be very well lit, especially those areas that are in the distance.

· Different vision: different people have different vision. For some it is weaker. Moreover, the eye's ability to quickly adjust to objects at different distances deteriorates with age. Many glasses are required in 40-50 years. Therefore, it is especially important that the workplace of older workers is well lit.

Visual acuity test

· You can test your visual acuity by trying to read the text above.

· If you have difficulty reading this text in sufficient light, then you need to contact an ophthalmologist, you may need to prescribe glasses.

Lighting requirements in the workplace require good use of light while avoiding blinding sunlight or other light sources.

Daylight

Artificial lighting is not as recommended as natural daylight, but daylight can vary depending on the time of year and similar conditions. Consequently, the required amount of lighting is determined regardless of the available daylight.

Adequate lighting should illuminate the entire work area and should not obscure any part of the body or machine. This applies to both daylight and artificial lighting.

It is important to make the best use of daylight. Do not store materials in such a way that they impede the flow of daylight. Windows must be clean both outside and inside. If the window faces a wall, then that wall must be painted White color to reflect more on the work area daylight.

In industrial plants, daylight can be increased by using roof windows. However, you need to think about additional lighting, as sunlight may not be enough, depending on the time of year.

The interior walls of the factory building should be painted in light colors to the best way use both sunlight and artificial lighting.

Recommendations for planning, location and screening of computer equipment in office premises. Work with a dark monitor. And in general, the lighting should be a little more subdued than in other rooms.

contrast lighting

To distinguish between objects with poor contrast, you have to strain your eyesight. It is especially difficult to distinguish objects in semi-darkness. Moving from a brightly lit area to a darkened room can even be dangerous, as it takes time for the eyes to adjust to the difference in light, and partial loss of vision is possible.

On highways, harsh shadows can lead to accidents in low light conditions. This problem exists in many workplaces.

Reflection

Reflection is the property of a surface to reflect light. The darker the surface, the less light it will reflect and the more light is required to illuminate the room. Light reflected directly into the eyes can cause blinding.

A) Light blinding a worker due to a lamp hanging low from the ceiling.

B) reflected blinding light

The eyes adjust to the brightness of the light, in this case from a lamp or a reflection. The pupil of the eye constantly contracts due to bright light. In the right picture, the eyes must constantly adjust to the reflection. In both cases, it is very difficult to view the work material, which causes fatigue and headache.

Bright light

A blinding brilliance is caused by looking at a light that is brighter than what the eye can accommodate. This happens when an unshaded artificial light source hangs too low, or when sunlight is directed directly at the workplace.

Reflected glare occurs when light reflects off shiny surfaces. This can be avoided by properly positioning the correct type of lamp.

Blinding is due to:

1. a low-lying lamp hanging from the ceiling

2. Misdirected local lighting

3. reflected light

Lighting Requirements

Basically, the light should fall on the materials or objects with which we are working. As a general rule, the light source should be placed behind and to the left unless the person is left-handed. This applies to local lighting in the workplace.

Factors that determine the amount of light include:

The nature of the work being done (for example, more light is needed to complete the precise work)

the ability of surrounding surfaces to reflect light

the size, shape and reflectivity of objects and whether the object is easily distinguishable against the surrounding background

workers' vision.

Remember!

· Lighting problems are a combination of light sources, glare, reflections, and obscurations. Good lighting requires light painted walls!

Questions:

· What can be done to make better use of the light coming through windows, doors and skylights?

· Don't you think that your room needs more artificial lighting in addition to natural?

How is the light positioned in relation to the workplace? Is there a blackout in the workplace?

Do you have problems with blinding daylight? Are there blinding lights?

· Is the workplace of older workers adequately lit?

Poor general lighting and lack of local lighting causes awkward posture and associated fatigue, and reduces productivity and quality of work. General lighting should provide an even distribution of light throughout the work area. The intensity of the light is determined by the nature of the work being done. Stronger light is needed when doing work related to fine details when performing precise operations. Practice shows that there is only one way to fulfill this condition - the installation of local lighting. The color scheme of the room itself is very important. The floor, walls and ceiling should be painted in light colors.

General and local lighting

Typically, lighting in work areas is general or a combination of general and local lighting.

General lighting is provided by lamps on the ceiling or walls. General lighting illuminates the entire working area.

· Local lighting is lighting in the immediate vicinity of the workplace to illuminate objects.

· The combination of general and local lighting allows you to best illuminate the workplace.

Cleaning and maintenance of lighting fixtures

The amount of light supplied decreases as the light source ages. The most important reasons:

deterioration of the light source (lamps)

· dirty lighting

dirty room

Dirty reflectors or anti-dazzle devices.

The biggest cause of poor lighting is dirt on lamps or fixtures.

Fluorescent lamps and tubes age over time. After a certain period of time, they give only half of the original light. Therefore, it is not enough to replace burnt out light bulbs. They should all be replaced when there is not enough light in the room.

Ordinary light bulbs burn out the fastest, they also give the least light. Their service life is typically 1000 hours compared to 7000 hours for fluorescent lamps.

We can say that the pollution of lighting fixtures is determined by the work performed in a given room.

Even for economic reasons, lamps must be serviced regularly. The required illuminance standard is easier to achieve if lighting fixtures are kept clean and lamps are replaced.

Remember!

· It is important to service your lighting fixtures regularly. It also gives you the opportunity to think about how best to illuminate the premises.

Exercise:

Who is responsible for keeping lamps and windows clean?

· If a lamp burns out, who is responsible for replacing it?

Are there any special assignments that require local lighting?

· Have any lighting improvements been adopted? Describe them.

Noise influence

Not all sounds can be classified as noise. Noise is what we call sounds that we don't like.

AT last years the noise level has increased. The equipment, which has become much more productive and faster, has also increased the noise level. In large open work areas, noise is distributed throughout the area and may increase in intensity as additional equipment contributes to the increase in noise levels.

The perception of noise is always very individual, however, it is obvious that even hearing loss is possible, sometimes irreversible, if the noise level reaches too high levels.

Noise affects more than just hearing. Noise also affects blood circulation and creates tension in the body. After such phenomena, a person usually falls asleep badly. Noise can lead to:

Hearing impairment

Difficulty in communication between people

irritation.

People perceive sounds differently. What you find pleasant and pleasing to the ear may seem noisy and unpleasant to others. Remember that whenever a person is exposed to loud noise, permanent hearing loss can result.

Noise is an unpleasant sound

Noises that can cause injury

In some workplaces, the noise level can be so high that it can damage your hearing. Often noise is generated various types working equipment. Compressed air machines or a hand anvil also make a lot of noise.

Continuous noise at the level of 85-90 decibels and above is dangerous for hearing. If a worker drives more than 5 hours a day in an environment with this noise level, hearing loss can result. A sharp, unexpected loud sound in the immediate vicinity of the ear can also lead to hearing loss. Unfortunately, you cannot close your ears, as is the case with your eyes.

It is not only the direct impact of noise that negatively affects a person. In stressful work situations, annoying or overbearing noise can cause mental distress, which in turn can cause physical distress.

drowning noise

Drowning or blocking noise means that the sound we want to hear is difficult for other sounds to perceive. In the workplace, equipment noise can drown out the sound of a passing car or interfere with conversation. Similar problems exist in many industrial enterprises.

The sound level should not exceed 60-70 decibels if we have to carry on a conversation at a normal distance.

annoying noise

Annoying noise can manifest itself in various forms. The level of our perception of noise as an annoying factor can be very subjective, depending on whether we want this sound or not. Even low sound can be annoying.

Questions and tasks:

Do you ever find yourself at work where you can't hear what others are saying?

· Discuss the sources of noise that bother you the most in the workplace.

· Do you feel that sometimes the noise is so strong that it can damage your hearing?

hearing damage

If you have to work in an area with a high level of noise for a long time, this can lead to significant hearing loss. The ear is a very sensitive organ that needs to be protected.

The figure shows a cross section of the ear. Sound travels through the outer ear and vibrates the tympanic membrane in the three ear bones. The vibrations travel through a fluid contained in a tightly wound tube called the cochlea. The auditory nerve, which has endings in the cochlea, transmits a signal to the brain.

When a person is exposed to a lot of noise, the snail is the first to suffer. Very thin endings inside the cochlea are destroyed and die. This damage is irreparable. Recovery is not possible.

Different people have different degrees of susceptibility to noise. Some people's hearing can be damaged faster than others.

The picture shows a snail damaged by noise. About 1/3 of the nerve endings are completely destroyed. This makes it impossible to perceive high tones - hearing is damaged.

partial hearing loss

We must know that there is such a warning signal: if, after being in a noisy room, we find ourselves in a calmer environment and at first do not hear more faint sounds, then our hearing has deteriorated - this is called partial hearing loss. This type of loss is recoverable. After some time of rest, hearing will return to its normal level.

It is therefore important that those people who work in a noisy environment can take rest breaks in some quiet place. Partial hearing loss should serve as a warning. It is impossible to work for many years in such a noisy place so that the hearing loss does not become complete.

Disability

Hearing is an important way of perception that helps people communicate with the outside world. With complete or partial hearing loss, it becomes difficult to hear what other people are saying, listening to messages on radio and television.

Complete or partial hearing loss can have the following consequences:

Difficulty understanding other people's normal speech

it is difficult to understand what the masters or work colleagues say and what kind of sound signals they give

You may suffer from feelings of isolation as the person does not take part in conversations with colleagues during breaks or meetings with friends

You have to take breaks and relax more often than usual, because often you need to spend all your energy to do the work.

Remember!

Hearing tolerates low sounds more easily than high ones. Therefore, when hearing is damaged, the perception of high-pitched sounds disappears most quickly. We may not notice this because we hear normal speech. It is only within a few years that the hearing loss becomes so obvious that it becomes difficult for us to understand other people's speech.

Miners experience very high noise levels. In addition, their body vibrates so much that it affects blood circulation and causes damage to muscles and ligaments.

Vibration combined with noise

Noise may be due to vibration, flowing gases or liquids. Many machines or hand tools motorized also transmit their vibrations to the human body. They can cause damage to muscles, ligaments and affect blood circulation. The most painful example of vibration-related injury is among workers using pneumatic drills, saws, or jackhammers.

Vibrations of the whole body are also a big problem. An operator sitting on a vibrating seat for a long time or operating a sawmill is also exposed to strong vibrations. In this case, the vibration frequency is much lower, although they are combined with low engine noise. Vibrations experienced by an operator working on a sawmill cause considerable distress as well as damage to internal organs.

Questions and tasks:

· Do you or your colleagues suffer from partial hearing loss or deafness?

What problems can deafness cause? At work? Out of work?

· The problem of hearing loss due to the noise of working machines has long been known to us. What do you think of her? Do you see it as a necessary evil?

· What are the possible negative effects of working in a very noisy environment? Make a list of possible health and safety implications.

decibels

A sound may consist of a single pure tone, but most often it is a combination of many tones of different levels (loudness) and pitches (high and low frequency). The noise level is measured in decibels. Height is measured in hertz.

If we think that sound is disturbing, it is not due to volume alone. Pitch is also a strong factor. High tones are more annoying than low tones. Clear sounds can cause anxiety and hearing damage even more than complex tones.

The following table shows the level of various sounds in decibels. The most commonly used decibels are because they are closest to the effects of noise on the ear.

Characteristics of the decibel scale

Noises from different sources are mixed with each other. The overall noise level in any location increases as the number of noise sources increases. Due to the specific characteristics of the decibel scale, it is not possible to simply sum the various noise levels. Two different noise sources, each with a noise level of 80 dB, together give a level of 83 dB, not 160 dB.

Another important characteristic is that changes from 80 to 83 dB are perceived by the ear as strongly as a transition from 40 to 43 dB.

Impact on a person	Noise level in decibels (db)	Sound source
Severe lesions		Reactive plane rivet hammer
PAIN THRESHOLD
Defeat		aircraft propeller Jackhammer Chain Saw Sheet rolling shop heavy truck
Danger		Busy street
Inability to hear speech		A car
annoying		normal conversation Talk Quiet music on the radio Calm city apartment rustle of leaves

A change of 3 dB, as in our example, always has the same effect on our perception of noise, regardless of the original noise level.

It is important to keep these facts in mind when discussing the intensity of noise and the transition from one level to another. When we say that the noise level has decreased from 90 to 80 dB, this may seem insignificant, but given the characteristics of the noise scale feature, this means that such a reduction would have the same effect if we removed 9 out of 10 noisy machines from the shop.

Remember!

· if you feel that you cannot speak in a normal voice with the interlocutor, being at arm's length from him, then the noise level is too high.

Questions and tasks:

List the sources of noise affecting you.

· Can you name which parts of the machine or elements are the main source of noise.

Is it possible to separate the noisy work in your place from the quiet work?

Noise Control Methods

Equipment and production processes

Many noise sources produce and transmit sound both through the air and through the structure of the machine. Thus, it is necessary to try to reduce the level of noise emanating from the equipment and spreading throughout the production room. It can be difficult to reduce noise levels from equipment and production processes without interrupting production or reducing output. However, try:

isolate the entire machine or a particularly noisy part of the machine

Regularly service the equipment to keep it in order and thus reduce the noise level

reduce vibration of components and upholstery

Replace metal parts with parts made of sound-absorbing material, such as plastic, rubber or other materials

· to slow down the braking time of piston equipment.

The well-designed sound-absorbing housing can reduce the noise level by up to 55db. If the noise level in the workplace is above 80 dB, measures must be taken to reduce the overall background noise. This can be the installation of sound-absorbing covers around the machine or the use of personal hearing protection. It is preferable to use sound-absorbing covers around noise sources or other similar measures, rather than ear plugs. However, at the time when the improvement will be made, it is necessary, without waiting for their completion, to use personal protective equipment.

Noisy equipment

Noisy equipment can be made less noisy without any complex measures. You can do the following:

Installing an outlet silencer

use of a different type of pneumatic equipment with fewer parts operating at high frequencies

replacement of equipment with a less noisy model, for example, fans with appropriate blades

good fit of noise-producing parts

isolation or shielding of noisy equipment from the workplace.

Working with materials

The noise caused by material handling can be greatly reduced. Avoid knocking on materials, especially when transporting equipment.

Also don't forget:

reduce the height of the storage of materials so that they do not fall off the shelves or from the racks

Reinforce sheet metal structures that are overstocked with bags or materials or cover them with sound-absorbing material

Reduce harsh impacts by applying rubber or plastic covers

Reduce conveyor speed

· install several conveyor belts on conveyors to distribute the load and reduce speed.

There are other ways to reduce the noise level when transporting parts:

The conveyor belt can be raised and lowered hydraulically. At the end of the belt is a drum with rubber brake blocks attached to the inside of the container. The drum rises automatically. The free fall height is always the same as the distance between the last block and the top level of the material in the container.

Some plants use material transport chutes made of sheet iron, plastic or wood. When the conveyed material hits the chute, a lot of noise is produced.

Noise can be reduced by covering the outer part of the gutter with sound-absorbing material. When purchasing a new transport chute, choose this design.

The following example shows what steps can be taken to reduce the level of resonance, i.e. sound that is amplified by contact with rims or wheels.

EXAMPLE. In an automotive plant with multiple production lines, the noise on some lines is usually higher than on others. Let's say high-frequency noise occurs on the cabinet grinding line, which distracts people working in the same room.

MEASURES. Place light barriers on both sides of the production line, and install a canopy of sound-absorbing material on top, which separates other workers from the noise generated during operation. But when working in this area, you still need to use headphones.

Work rooms

Noise propagation throughout the work area can be reduced if:

cover the ceiling and walls with sound-absorbing material (porous)

Apply noise-absorbing screens

Establish a noise-protective control zone and rest rooms.

Installing sound-absorbing material on the ceiling reduces the overall noise level in the room. The sound-absorbing partition on the ceiling can be replaced with panels.

If noise sources are isolated by a wall or protected by a cover, the noise level can be reduced both close to the noise source and at a distance from it. Then those people who work with quiet equipment at a quiet job are not distracted by the noise around them.

The spread of noise throughout the room can be reduced and the noise level reduced if the ceiling and walls are covered with sound-absorbing material.

It is often necessary to place equipment that produces noise on elastic mats or stands. This isolates the vibrations and also prevents them from propagating along the building structure, pipes, etc. Large heavy machines should be placed on their own foundation separate from the floor of the entire workshop.

Remember!

In practice, a combination of several methods of noise reduction is usually used:

Reducing the overall background noise

Noise source isolation

sound absorbing materials.

Often noise reduction is costly, so other methods must be used. For example, you can try to use barriers made of porous material.

Questions:

How can you tell if a workplace is too noisy?

· Have you applied any of the suggestions made in this section to the equipment?

What measures can you take now to reduce the noise source?

Hearing protection

Headphones, earplugs

Noise, which can be hazardous to health, is reduced by technical measures. If this is not possible, then it is necessary to use personal protective equipment, for example, you can use headphones or ear plugs.

Earplugs used.

L. Bata - acoustic fibers.

2. Plastic-coated acoustic fibers.

3. Elastic plastic.

4. Earplugs made of reusable plastic.

It is important that earmuffs are worn at all times while a person is exposed to high levels of noise, even if the worker removes them briefly, this still poses a serious threat to hearing.

Remember!

· If you have to use headphones or ear plugs, they must be carefully checked to be effective, they must fit snugly. Keep in mind that if the earmuffs or earplugs do not fit snugly, they will not protect your ears. Earplugs should be regularly cleaned, repaired and replaced as needed. In order to achieve consistent use of hearing protection, the cooperation of craftsmen and workers is required.

Questions:

· Do you have noise suppression equipment at your disposal?

· If yes, are they used? Are they cleaned regularly?

· Don't you think that there is a job for which the use of protective equipment against noise is mandatory?

Why do many workers dislike using these tools?

USEFUL TIPS

Heat and ventilation

There is sufficient natural ventilation through windows and openings.

· Radiation from the roof and walls is minimized by using suitable material and colour.

Good ventilation on the roof and ceiling.

· There are sufficient fans to keep the air always clean and pleasant.

· In hot shops air circulates by means of fans.

· Hot surfaces are insulated and kept at a distance.

· There is a barrier between workers and heat sources.

· Heat-protective aprons or clothing are used where appropriate.

· When using air conditioners, the appropriate type is used, taking into account air pollution during the production process.

· Avoid hypothermia and drafts caused by air conditioners.

· Heavy physical labor should be avoided in hot rooms.

· Avoid working in confined spaces at high temperatures.

· When working in a hot place, take the required number of breaks.

· Cool drinking water should be available near the workplace.

Lighting

· Sufficient daylight, not dimmed and correctly falling, enters the workplace.

· A glazed roof is used to increase the light.

Light colors are used to paint the walls.

· There is no blinding light from ceiling lamps and spotlights.

· Avoid glare due to strongly reflected light.

· Avoid highly contrasting shadows.

· General lighting appropriate to the type of work being done.

· Local lighting is used as an auxiliary, in addition to the general one, especially for precise work.

· All lamps are replaced regularly.

· Lamps and fixtures are regularly cleaned.

· Noisy parts of machines are shielded or completely covered.

· To avoid noise during operation, the machine is regularly adjusted.

· Noise-absorbing material is used for the ceiling, walls and machine covers.

Noisy equipment or parts are replaced with modern models.

· A protective screen is used to prevent the spread of noise.

· The height of objects in containers is kept to a minimum to avoid sound reflections over long distances.

· Workers working on quieter equipment are not exposed to noise from other machines.

· Workers in the noisiest areas are more likely to move to other work areas to avoid staying too long in the noisy area.

· If possible, the transmission of vibrations from machines to the hands of the worker is reduced.

· When noise reaches 85-95 dB, use headphones.

Working area is a space up to 2 meters in height from the floor level or platform with places for permanent or temporary stay of workers. A workplace is considered to be permanent if the employee spends more than 50% of the working time per shift or more than 2 hours per shift.

Indicators characterizing the microclimate in the working area are: air temperature T, 0 C; relative air humidity φ, %; air velocity V, m/s; the intensity of thermal exposure of workers from heated surfaces of equipment, products and open sources J, W / m 2.

Optimal- a combination of microclimate indicators that provides a person with a feeling of thermal comfort during the shift without disturbing the thermoregulation mechanism and does not cause deviations in health.

Permissible- established according to the criteria of the permissible and functional state of a person for the period of the shift. They do not cause health problems, but can lead to sensations of thermal discomfort.

The optimal and permissible values ​​of temperature, relative humidity and air velocity are set taking into account the period of the year, the category of work performed by the severity and time of work.

Periods of the year conditionally divided into: cold (with an average monthly outdoor temperature of less than +10 ° C); warm (with an average monthly outdoor temperature of more than +10 ° C).

category 1- light physical work - activities with energy consumption up to 150 kcal / h (174 W). To category 1a include work performed while sitting, without a large physical. voltage. To category 1b - work performed while sitting, standing or walking and some physical. tension;

category 2- physical work of moderate severity - activities with energy costs 151 - 250 kcal / h (175 - 290 W). To category 2a include work related to walking, moving small items in a standing position. To category 2b - work related to walking, moving weights up to 10 kg and moderate physical exertion.

The intensity of thermal exposure from open sources should not exceed 140 W/m 2 . At the same time, more than 25% of the body surface should not be exposed to radiation. The temperature of the external surfaces of the equipment should not exceed 45 ° C.

The required state of the air environment in the working area can be ensured by the implementation of certain measures, the main of which include: mechanization and automation of production processes, remote control; installation of ventilation and heating systems; protection from sources of thermal radiation (thermal insulation of heated surfaces, shielding of radiation sources and workplaces, use of personal protective equipment, rational mode work and leisure).

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Introduction

1. Microclimate and its impact on human health and performance

2. The microclimate of the workplace

3. Instruments for measuring microclimate indicators

3.1 Air temperature

3.2 Air flow rate

3.3 Relative humidity

4. Hygienic regulation industrial microclimate

5. Means of protection from the industrial microclimate

Conclusion

List of used literature

INTRODUCTION

Microclimate- these are meteorological conditions that are determined by the totality of physical parameters of the air environment acting on the human body in small open or closed spaces (up to tens and hundreds of meters in diameter). The indicators characterizing the microclimate of industrial premises are: temperature, humidity, air velocity and thermal radiation.

In this control work, we will consider the impact on the human body, the regulation of the microclimate, means of protection and many other facts. This control work is familiarization for the preservation of health, the creation of a comfortable and conforming to the regulatory parameters of the state of the environment in the workplace production environment, in everyday life and recreation areas of a person.

1. MICROCLIMATE AND ITS IMPACT ON HUMAN HEALTH AND WORKABILITY

The microclimate of industrial premises is the climate of the internal environment of these premises, which is determined by the combinations of temperature, humidity, and air velocity acting on the human body. The microclimate affects the process of heat transfer and the nature of the work. Prolonged exposure of a person to unfavorable conditions sharply worsens his state of health, reduces labor productivity, and leads to illness.

1) exposure to high temperature quickly tires, can lead to overheating of the body, heat stroke or occupational diseases. industrial hygienic microclimate humidity

2) low temperature - local or general cooling of the body, the cause of colds or frostbite.

3) high relative humidity at high temperature contributes to overheating of the body; when low, it enhances heat transfer from the surface of the skin, which leads to hypothermia.

4) low humidity causes drying of the mucous membranes of the respiratory tract.

2. WORKPLACE MICROCLIMATE

During any work and even at rest (in sleep), a person expends energy, the equivalent of which is released from the body in the form of heat. Environment should adequately absorb heat. If the microclimate does not correspond to the work performed, the body may overheat or become cold.

The most efficient way of heat transfer is radiation Q glad. Next comes the heat transfer by contact. Q knd and moisture evaporation Q Spanish On convective heat transfer and heat loss with respiration q accounts for no more than 5% (Fig. 15.1).

When the allocated and allocated are equal Q into the environment heat can be spoken of comfort meteorological conditions:

Q= Q happy + Q cnd + Q and cn + q.

The efficiency of the channels in the total amount of heat that appears in the exchange process is distributed as follows:

Rice. 15.1 Efficiency of heat exchange channels

The normalized components of the microclimate are affected by the category of work, which is determined on the basis of the total energy consumption of the body in kcal / h (W). According to this indicator, the work is divided into several categories.

CategoryIa. Work with an intensity of energy consumption up to 120 kcal / h (up to 139 W), carried out while sitting and accompanied by slight physical stress (a number of professions in precision instrumentation and engineering enterprises, in watchmaking, clothing production, in management, etc.).

CategoryIb. Works with an energy consumption intensity of 121-150 kcal / h (140 -174 W), performed while sitting, standing or walking and accompanied by some physical stress (a number of professions in the printing industry, in communications enterprises, controllers, craftsmen in various types of production, etc. . P.).

CategoryIIa. Work with an energy consumption intensity of 151-200 kcal / h (175 - 232 W), associated with constant walking, moving small (up to 1 kg) products or objects in a standing or sitting position and requiring a certain physical stress (a number of professions in mechanical assembly shops engineering enterprises, in spinning and weaving, etc.).

CategoryIIb. Work with an energy consumption intensity of 201 - 250 kcal / h (233 -290 W), associated with walking, moving and carrying loads up to 10 kg and accompanied by moderate physical stress (a number of professions in mechanized foundry, rolling, forging, thermal, welding shops, machine-building and metallurgical enterprises, etc.).

CategoryIII. Works with energy consumption of more than 250 kcal / h (more than 290 W), associated with constant movement, moving significant (over 10 kg) weights and requiring great physical effort (a number of professions in forge shops with manual forging, foundries with manual stuffing and pouring of flasks etc.).

The efficiency of heat exchange channels is determined by the following normalized microclimate indicators:

Air temperature, °C;

Temperature of enclosing surfaces, °С;

Air velocity, m/s;

Relative humidity, %;

intensity of thermal exposure, W / m 2.

3. TOOLS FOR MEASURING MICROCLIMATE INDICATORS

3.1 Air temperature

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It is measured with any thermometer, with an error not higher than ± 0.2 ° С. For this purpose, it is better to use a stick thermometer, in which the divisions are located directly on the body of the device. This eliminates unauthorized movement of the scale relative to the capillary, reducing the measurement error. Currently widely used electronic devices, for example, the domestic thermal anemometer TAM-1 with a measurement range of 0.1 to 2.0 m/s, temperature and humidity meters TKA-TV or testo 415 made in Germany (Fig. 1). All devices are powered by batteries that provide sufficient service life for certification. At the same time, the thermohygrometer testo 415 measures both rms and maximum value.

3 .2 Airspeedcurrent

The air flow rate is determined in various ways. The operation of the simplest device - catathermometer is based on the intensity of heat exchange with the environment, which is why it is also called a thermal anemometer. The advantage of the device is that it covers the entire range of normalized air flow rates. With it, you can determine the air speed in the range of 0.02 - 0.5 m / s.

Of the mechanical instruments, a vane anemometer of the ASO-3 type (measurement limits 0.3-5.0 m/s) has limited use due to the high lower measurement limit. It is equipped with a multi-scale dial, consisting of a main scale and two auxiliaries.

3 . 3 Relative humidity

Relative humidity is the ratio of absolute humidity (numerator) to maximum (denominator), expressed as a percentage, characterizes the moisture content in the volume of air:

where values E and E" - moisture content at indications of dry t dry and wet t vlzh thermometers are accepted according to psychrometric tables.

Values t dry and t vlzh obtained using an aspiration psychrometer.

Relative humidity is conveniently measured with digital instruments, for example, a domestic-made IVA-6 thermohygrometer.

In addition to relative humidity, it measures air temperature. The thermohygrometer fully meets the requirements for certification of workplaces in terms of working conditions.

At workplaces with a heating microclimate (maintenance of boiler plants and heat points, welding and blacksmithing, work clothes washing points, etc.) regardless of the season and in open areas during the warm season (construction, repair, travel and similar work), the indicator characterizing the microclimate is the intensity of thermal radiation. Its value is characterized by the index thermal naenvironment loads TNS.

This empirical integral indicator characterizes the combined (combined) effect of microclimate parameters (temperature, humidity, air velocity and thermal radiation) on the human body and evaluates it with a one-digit indicator in degrees. For the first time it was established by the international standard ISO 7243-1982 "Environment with elevated temperature - assessment of the effect of thermal load on a working person, based on the temperature index for wet and ball bulb thermometers" and is designated as WBG - index.

The index of the thermal load of the environment is recommended to be used for an integral assessment of the thermal load of the environment at workplaces where the air velocity does not exceed 0.6 m/s, and the intensity of thermal radiation is 1200 W/m 2 . The values ​​of the THC - index should not go beyond the recommended values ​​(Table 1)

Table 1. The values ​​of the thermal load of the environment for the prevention of overheating of the body

A radiometer can be used to measure the intensity of thermal radiation (W / m 2) Argus-03 domestic production. It is a compact, battery-powered instrument with a receiver field of view of at least 160 degrees.

Automated systems for measuring THC - index ( WBGT- index according to the international standard ISO 7243) can be either single or multi-channel. They allow you to perform the necessary measurements in parallel at three points and give the result to the built-in display and / or to the printer.

To measure the intensity of thermal radiation, radiometers are used with a viewing angle of the receiver of at least 160 ° and sensitivity in the infrared and visible regions of the spectrum. One of them is a radiometer of the type Argus-03. Actinometer type devices can also be used.

Microclimate indicators are measured at an outside air temperature that differs from the average winter or summer values ​​by no more than 5 ° C.

In order to protect personnel from overheating or hypothermia, the total time

stay at the workplace per shift should be limited - time protection. The average shift air temperature is calculated by the formula:

where t i and t i - temperature (° C) and length of stay (min) of the worker on i- that section of the workplace.

When choosing sites and measurement time, it is necessary to take into account all factors affecting the microclimate of workplaces (phases of the technological process, the functioning of ventilation and heating systems, etc.). Microclimate indicators are measured at least 3 times per shift (at the beginning, middle and end). In case of fluctuations due to technological and other reasons, additional measurements are taken at the highest and lowest thermal loads on workers. If the workplace is several sections of the production premises, measurements are carried out on each of them.

In rooms with a high density of workplaces in the absence of sources of local heat release, cooling or moisture release, the areas for measuring microclimate parameters should be distributed evenly over the area: up to 100m 2 - 4 areas; 100 - 400m 2 - 8 plots; over 400m 2 - the number of sections is determined by the distance between them, which should not exceed 10m.

4. HYGIENIC REGULATION OF INDUSTRIAL MICROCLIMATE

The norms for the parameters of meteorological conditions in industrial premises are regulated by GOST 12.1.005-88 "General sanitary and hygienic requirements for the air of the working area". The standard establishes requirements for indicators of air temperature, its relative humidity, air velocity for the working area of ​​industrial premises in the form of optimal and permissible values, taking into account the period of the year and the severity of labor activity.

The norms of parameters of meteorological conditions are established for the working area - a space up to 2 meters high above the floor level or a platform on which the place of permanent or temporary stay of the worker is located. A permanent place is a place where an employee spends more than 50% of his working time or more than 2 hours continuously.

Normalized microclimate parameters in industrial premises SanPiN 2.2.4.546-96 for periods of the year: cold or warm. Cold period of the year characterized by an average daily outdoor temperature of + 10 ° C and below, and warm - above +10°С.

Average daily outdoor temperature - the average value of the outdoor air temperature measured at certain hours of the day at regular intervals. It is taken according to the meteorological service. In accordance with the specified sanitary norms and rules, the microclimate parameters of industrial premises can be optimal and acceptable.

Optimal microclimatic conditions established according to the criteria for the optimal thermal and functional state of a person. They provide a general and local feeling of thermal comfort during an 8-hour work shift with minimal stress on thermoregulation mechanisms, do not cause deviations in health status, create preconditions for a high level of performance, and therefore are preferred in the workplace.

The list of other jobs and types of work, in which optimal microclimate values ​​must be ensured, are determined by the Sanitary Rules for individual industries and other documents agreed with the bodies of the State Sanitary and Epidemiological Surveillance in the prescribed manner.

Optimum indicators of the microclimate at the workplace stakh are recognized as those that correspond to the recommended values ​​(Table 2), in relation to the work of various categories in the cold and warm periods of the year. Changes in air temperature along the height and horizontally, as well as changes in air temperature during the shift, should not exceed 2 ° C and not go beyond the specified limits.

The optimal indicators of the microclimate must be observed at the workplaces of industrial premises where operator-type work is performed associated with neuro-emotional stress (in cabins, on consoles and control posts for technological processes, in computer rooms, etc.).

table 2. Optimalindicatorsmicroclimate at workplaces of industrial premiseseniyah (at a relative humidity of 40-60%)

Permissible microclimatic conditions established according to the criteria for the permissible thermal and functional state of a person for the period of an 8-hour work shift. They do not cause damage or health problems, but can lead to general and local sensations of thermal discomfort, tension in the mechanisms of thermoregulation, deterioration in well-being and decreased performance.

Permissible microclimate indicators are established in cases where, due to technological requirements, technical and economically justified reasons, optimal values ​​\u200b\u200bcannot be provided. At the same time, the air temperature difference along the height should not exceed 3°C, and horizontally and during the shift should not exceed 4°C for work category I; in categories II - 5°С; at categories III - 6°С.

During the warm period of the year, when the air temperature at the workplace is 26-28°C, its movement speed should correspond to the recommended range, and relative humidity at an air temperature of 25°C and above should not go beyond the established limits.

If at least one of the parameters does not correspond to the given values, the working conditions at the workplace are recognized as unsatisfactory, and the workplace itself is characterized as “conditionally certified”. This means that the parameters of the determining factor must be brought to acceptable values.

For measurements of microclimate indicators, it is necessary to choose devices that provide errors in the result.

At workplaces with a heating microclimate (maintenance of boiler plants and heat points, welding and blacksmithing, work clothes washing points, etc.) regardless of the season and in open areas during the warm season (construction, repair, travel and similar work), The indicator of the microclimate is the intensity of thermal radiation. The empirical integral indicator THC reflects the combined effect of all microclimate factors, including thermal exposure.

5 . MEANS OF PROTECTION FROM INDUSTRIAL MICROCLIMATE

In production conditions, there are situations when, due to the requirements of the technological process or technical unattainability and economic inexpediency, it is impossible to provide acceptable standard values ​​for the parameters of meteorological conditions; in such cases, special measures are taken to protect workers from possible overheating or cooling.

Main preventive actions in production:

Mechanization and automation of heavy and labor-intensive work, the implementation of which is accompanied by excessive heat release in the human body;

Remote control of heat-radiating processes and devices, which eliminates the need for workers to stay in the infrared radiation zone;

Installation of protective screens, air and water curtains that protect workplaces from thermal radiation;

Rational placement and thermal insulation of equipment, apparatus, communications and other sources that radiate heat to workplaces;

Installation of thermal curtains at the entrance to the workshop to prevent the entry of cold outside air into the premises;

Shelter of sources of intense moisture release with casings, covers or local suction devices;

The device of aeration or mechanical ventilation in the presence of powerful sources of heat and moisture release in the production premises;

The device in hot shops of rooms for short-term rest, with the supply of purified and cooled air to them;

The device of specially equipped rooms for periodic heating of those working for a long time in the cold.

CONCLUSION

In conclusion of the control work, we can conclude about the microclimate that a certain combination of temperature, relative humidity and air velocity is important for a person’s thermal well-being.

The microclimate also determines the need to develop physiologically based parameters of temperature, humidity and air velocity, which would take into account the specifics of various industries, a variety of technological processes, and labor intensity. Such studies to assess the impact of a set of parameters of meteorological conditions on human heat transfer were carried out by the institutes of occupational health. Based on this, GOST 12.1.005-88 "General sanitary and hygienic requirements for the air of the working area" was created. The main content of preventive supervision is control over compliance with sanitary norms and rules for design and construction industrial facilities. The task of the current sanitary supervision is to control compliance with sanitary legislation at operating enterprises. One of the elements of the current sanitary supervision is the study of working conditions at industrial enterprises in order to prevent occupational and general morbidity. Rationing of the production microclimate is regulated by the same GOST.

To measure air temperature, GOST 12.1.005-88 recommends using aspiration psychrometers to measure temperature, especially since the study of weather conditions involves the simultaneous determination of air humidity, and to measure the relative humidity of the air, an ASSMAN aspiration psychrometer type M-34.

Anemometers of various designs are used to measure the speed of air movement. The choice of anemometer type is determined depending on the objectives of the study and the magnitude of the measured air velocity.

Vane anemometer ASO-3 allows you to measure the speed of air movement in the range from 1 to 10 m/s.

Cup anemometer is designed to measure the average speed of the air flow from I to 20 m/s.

The spherical catathermometer is used to measure low air velocities.

The main thing is to use technical means to prevent or reduce the impact on workers of harmful or dangerous production factors, as well as to protect against pollution.

LIST OF USED LITERATURE

1. Kuznetsov K.B., Vasin V.K., Kupaev V.I., Chernov E.D. Life safety. Part 1. Life safety in railway transport: Textbook / Ed. K.B Kuznetsova. M.: Route, 2005 - 576s.

2. K. B. Kuznetsov, V. K. Vasin, V. I. Bekasov, A. P. Mezentsev, and Yu. Life safety. Part 2. Occupational safety in railway transport: Textbook / Ed. K.B Kuznetsova. M.: Route, 2006 - 536s.

3. Troshunin V.V. Zvigintseva G.V. Ivashova Z.I. The study of microclimate indicators in the working area of ​​industrial premises: Laboratory work. Yekaterinburg, 2004 - 21s.

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