Basic lighting characteristics. The main lighting characteristics of lamps. Lighting parameters
Basic lighting characteristics. The sensation of vision occurs under the influence of light, which is electromagnetic radiation with a wavelength of 0.38 ... 0.76 microns. The sensitivity of vision is maximum to electromagnetic radiation with a wavelength of 0.555 microns (yellow-green color) and decreases towards the boundaries of the visible spectrum.
Lighting is characterized by quantitative and qualitative indicators.
Quantitative indicators include:
- · light flow F- part of the radiant stream, perceived by a person as light; characterizes the power of light radiation, measured in lumens (lm);
- · the power of light J-- spatial density of the light flux; defined as the ratio of luminous flux DF, emanating from the source and uniformly propagating inside the elementary solid angle DS, to the value of this angle; J = DF /DS; measured in candelas (cd);
- · illumination E is the surface density of the light flux; defined as the ratio of luminous flux DF, uniformly incident on the illuminated surface, to its area DS(m 2); E= DF / DS measured in lux (lx);
- · brightness L surface at an angle b to the normal is the ratio of the light intensity DJb, radiated, illuminated or luminous surface in this direction, to the area DS projections of this surface onto a plane perpendicular to this direction;
measured in cd m -2 .
For a qualitative assessment of the conditions of visual work, such indicators as the background, the contrast of the object with the background, the pulsation coefficient of illumination, and the spectral composition of light are used.
Background-- this is the surface on which the distinction of the object takes place. The background is characterized by the ability of the surface to reflect the light flux incident on it. This ability (reflection coefficient With) is defined as the ratio of the light flux reflected from the surface F neg to the light stream falling on it F pad ;
c= F neg/ F pad .
Depending on the color and texture of the surface, the values of the reflection coefficient ^ are in the range of 0.02 ... 0.95; at With? 0.4 background is considered light; at With\u003d 0.2 ... 0.4 - average and at With? 0.2 - dark.
The contrast of the object with the background To-- the degree of distinction between the object and the background -- is characterized by the ratio of the brightness of the object under consideration (points, lines, signs, spots, cracks, risks or other elements) and the background; To = (L op -L o)/ L op is considered large if ? 0.5 (the object stands out sharply against the background), medium at k = 0.2 ... 0.5 (the object and background differ noticeably in brightness) and small at k ? 0.2 (the object is barely visible against the background).
Illumination ripple factorTo e is a criterion for the depth of fluctuations in illumination as a result of a change in the time of the luminous flux:
To e = 100(E max -E min)/(2Ecp)
Where E max , E min, E cp -- maximum, minimum and average illumination values for the oscillation period; for discharge lamps To e=25...65%, for conventional incandescent lamps To e= 7%, for halogen incandescent lamps To e = 1 %.
Systems and types of lighting. When illuminating industrial premises, natural lighting is used, created by direct solar clouds and diffused light of the sky and changing depending on the geographical latitude, time of year and day, degree of cloudiness and transparency of the atmosphere; artificial lighting created by electric light sources, and combined lighting, in which natural lighting that is insufficient in terms of burrows is supplemented with artificial lighting.
Structurally daylight subdivided into lateral (one- and two-sided), carried out through light openings in the outer walls; upper - through light openings in the roof and ceilings; combined - a combination of top and side lighting.
In classrooms, lateral left-sided natural lighting is used. With a room width of more than b m, it is imperative to arrange right-sided illumination. The direction of the main light flux in front and behind the students is not allowed.
artificial lighting according to the design, it can be of two types - general and combined. The general lighting system is used in rooms where the same type of work is carried out over the entire area (foundries, welding, galvanizing shops), as well as in administrative, office and storage rooms, in classrooms and classrooms of educational institutions. There are general uniform lighting (the luminous flux is distributed evenly over the entire area without taking into account the location of jobs) and general localized lighting (taking into account the location of jobs).
When performing precise visual work (for example, plumbing, turning, control) in places where the equipment creates deep, sharp shadows or work surfaces are located vertically (stamps, guillotine shears), along with general lighting, local lighting is used. The combination of local and general lighting is called combined lighting. The use of one local lighting inside the production premises is not allowed, since sharp shadows are formed, vision quickly gets tired and there is a danger of industrial injuries.
According to the functional purpose, artificial lighting is divided into working, emergency and special, which can be security, duty, evacuation, erythema (ultraviolet radiation contained in the spectral region from about 0 280 to 0 38 - 0 400 microns and having a beneficial effect in small doses on human and animal organisms), bactericidal, etc.
Work lighting designed to ensure the normal execution of the production process, the passage of people, traffic and is mandatory for all production facilities.
Emergency lighting arrange for the continuation of work in cases where a sudden shutdown of the working lighting (in case of accidents) and the associated violation of the normal maintenance of the equipment can cause an explosion, fire, poisoning of people, violation technological process etc.
The minimum illumination of working surfaces with emergency lighting should be 5% of the rated illumination of working lighting, but not less than 2 lux.
emergency lighting designed to ensure the evacuation of people from the production area in case of accidents and switching off the working lighting; organized in places dangerous for the passage of people: in stairwells, along the main aisles of industrial premises, which employ more than 50 people. The minimum illumination on the floor of the main passages and on the steps with evacuation lighting should be at least 0.5 lux, in open areas - at least 0.2 lux.
security lighting arrange along the borders of territories protected by special personnel. The lowest illumination at night is 0.5 lux.
signal lighting used to fix the boundaries of hazardous areas; it indicates the presence of a hazard or a safe escape route.
Quantities and parameters that determine the visual conditions of work
Luminous flux (F) - part of the radiant energy perceived by a person as light, characterizes the power of light radiation, measured in lumens (lm).
Illumination (E) is the surface density of the luminous flux, defined as the ratio of the luminous flux uniformly incident on the surface to its area.
Lux = 1 lumen/ 1 m^2
Light intensity (I) - spatial flux density, defined as the ratio of the luminous flux emanating from a light source and uniformly propagating inside an elementary solid angle, to the value of this angle. Measured in candela.
I (cd) \u003d F (km) / D (..)
The brightness (L) of an extended light source in a given direction is defined as the ratio of the luminous intensity emitted by the surface S in that direction to the projection area of the luminous surface onto a plane perpendicular to that direction.
L (cd / m^-2) = I / S cos α
The reflection coefficient ρ is characterized as the ratio of the light flux reflected from the surface to the light flux incident on it.
Ρ = Photographic / Ffalling
The background is the surface on which the object is distinguished.
The object of distinction is understood as the minimum element of the object under consideration, which must be distinguished for visual work.
The contrast of the object with the background - the degree of distinction between the object and the background - is determined by the ratio of the brightness of the object in question and the background.
K = (Lbackground - Lobject) * 100% / Lbackground
The contrast can be large (k>0.5), medium (0.2 - 0.5) and small (<0.2).
2. industrial lighting requirements
Compliance with the level of illumination of places and the nature of the lighting work performed.
quality of illumination - a fairly uniform distribution of brightness on the working surface and the surrounding area, the absence of sharp shadows, direct and reflected brilliance.
Constancy of illumination over time - in the working network, the operating voltage jumps, the luminous flux changes.
· the optimal direction of the flow emitted by lighting fixtures.
durability (1000 hours)
efficiency efficiency
electrical and fire safety
Convenience and ease of use
3. Types and systems of industrial lighting
Kinds:
natural; artificial; combined
Natural:
+: most eye-friendly spectrum. There are no energy costs, ease of use, reliability and safety.
-: unevenness and inconstancy in time (depends on the time of day, year)
depends on the latitude of the location of buildings, on the orientation of parts of the world, on obscuration by opposing buildings and trees.
Structurally, natural lighting is divided into:
lateral - through light openings in the outer walls (one-, two-sided)
Upper - through light openings (lanterns) in the coatings and through openings in the walls in places where the heights of buildings differ;
combined - a combination of top and side
Therefore, to distinguish between parts, KEO (factor of natural light) was introduced.
KEO \u003d Evn of the premises * 100% / E at the same time in the open area
Luxmeter device - max. common, for definition. KEO and normalize the dependence on the category of visual work:
A. Contrast
B. The contrast of the object with the background
For study. KEO audience > 1.5%
artificial lighting: helps to avoid imperfections naturally. lighting and ensure optimal light conditions. It can be general, local, combined.
Local lighting- achieved due to the density of the lamp, changing the power of lighting devices, the height of the suspension, due to the use. dec. luminaires with different reflection coefficient.
Uniform illumination– lighting that is evenly distributed.
local lighting- if necessary, supplements the general and concentrates an additional luminous flux on the slave. places.
Combined– a combination of local and general lighting.
The use of one local lighting is not allowed.
According to the functional purpose of the arts, lighting is divided into:
working; emergency; evacuation
security; duty; signal
Working- lighting, mandatory in all premises and in illuminated areas to ensure normal operation, movement of people and trade.
emergency– lighting, providing for the provision of min. illumination in the event of switching off the working lighting and connected. with this violation is normal. equipment maintenance. It must be nourished by self-sufficiency. source. Can go offline. The minimum illumination of working surfaces with emergency lighting should be 5% of the normalized illumination of working lighting, but not less than 2 lux.
evacuation- lighting designed to evacuate people from the premises in case of accidents and turn off the working lighting. Must provide at least 0.5 lux at floor level, in aisles and 0.2 lux in open areas.
Security– lighting in protected areas (linear dispatcher station).
Signal- lighting used to fix the boundary of the danger zone.
4. Regulation of artificial lighting
Rationing is carried out in accordance with SNiP.
Rationing depending on:
on the nature of the visual work (the size of the object of distinction)
from the system and type of lighting
background (light, dark)
from the contrast of the object with the background
from a light source
Art is normalized by quantitative (minimum illumination) and qualitative indicators (indicators of blindness, discomfort, pulsation coefficient of illumination).
Outdoor lighting must be controlled, independent of the lighting control inside the building. SNiP also normalizes the height of outdoor lighting installations to limit their blinding effect.
The calculation of artificial lighting is reduced to solving the following issues: the choice of a lighting system, the type of light sources, the norm of illumination, the type of lamps, the calculation of illumination at workplaces, the clarification of the placement and number of lamps, the determination of a single lamp power.
5. Sources of artificial light
Artificial lighting is carried out in the dark with the help of lighting devices, consisting of lamps.
Electric A luminaire is a combination of a light source and fittings.
The most important function of lighting fittings is the redistribution of the luminous flux, which increases the efficiency of the lighting installation.
Another no less important purpose of lighting fixtures is to protect the eyes of workers from exposure to excessively high brightness light sources. The light sources used have a bulb brightness that is tens and hundreds of times higher than the permissible brightness in the field of view.
Light sources for art lighting are gas discharge lamps and incandescent lamps, fluorescent lamps
Incandescent lamps:
Advantages:
Convenience in operation ; Ease of manufacture; Reliability
Low turn-on inertia
Flaws:
low efficiency - 18%; low light output; operating time 1000 hours
Fluorescent
Advantages:
· 8000 hours; high light output
Flaws:
twilight effect (for general lighting) - since the spectrum of these lamps is close to the spectrum of daylight, the eye also needs lighting (local)
more expensive; the presence of control equipment.
The industry produces fluorescent lamps: white (LB), warm white light (LTB), cold white light (LHB), daylight (LD), color corrected (LDC).
6. Classification of fixtures
A lamp is the identity of a light source and lighting fixtures.
Lighting fittings - designed to redistribute the luminous flux of the lamp, protect the eyes from glare, protect the source from mechanical damage and environmental exposure. environment.
According to the distribution of the light flux in space, lamps are distinguished:
direct light, at least 90% of the luminous flux per slave. turn.
Scattered light (milk ball)
· Predominantly reflected
· reflected light: from 60-90% of the luminous flux to the reflected light area. (at the cinema)
According to the design, the lamps are:
open: when the light source is in contact with the environment
protected
closed
explosion-proof,
· dustproof
waterproof
In rooms, the walls and ceilings of which have high reflective properties, it is necessary to install lamps with predominantly direct light, directing part of the light flux to the ceiling.
In high rooms it is rational to use lamps of concentrated light distribution. They significantly increase the luminous intensity of the lamp along the axis of the lamp and direct the main part of the light flux down, directly to the workplace. In rooms with a large area and low height, it is advisable to use lamps with a wider light distribution.
When choosing the type of luminaire, the most important requirement is to take into account environmental conditions. In rooms with a normal environment, there are no special requirements for the design of the luminaire. The same applies to damp and damp rooms, but with one requirement, the cartridge must have a housing made of insulating moisture-resistant materials. In particularly damp rooms, with a chemically active environment, fire and explosion hazard, the design of the luminaire must meet special requirements.
Local lighting fixtures are designed to illuminate the place of work, they are usually mounted on hinged brackets, which make it possible to move them and change the direction of the light flux.
7. Methods for calculating artificial lighting
method according to the coefficient of use of the luminous flux
dot method
power limit method
Calculation method according to the required illumination rate (for uniform illumination): design a lighting system, determine the number of lamps, lamp / lamp type, their power (80W), optimal placement, lamp suspension height.
Luminous flux utilization method:
The coefficient of use of the luminous flux, which gave the name to the calculation method, is determined according to SNiP 23-05 - 95, depending on the type of lamp, the reflectivity of the walls and ceiling, and the size of the room. According to the luminous flux obtained as a result of the calculation, the nearest standard lamp is selected and the required electric power is determined.
To calculate local illumination, as well as to calculate the illumination of a specific point on an inclined surface with general localized illumination, a point method is used..
Ea = Iα cosα / r^2
Ea - illumination of the horizontal surface at the calculated point A
Iα - light intensity in the direction from the source to point A
α is the angle m / y with the normal to the surface to which the point belongs, and the direction of the luminous intensity vector to point A
R is the distance from the lamp to A.
Power limit method
w - specific
PΣ - total number of W per m ^ 2 units. power
n - number of lamps
P1 - power of one lamp
8. Rationing of natural light
Natural lighting is characterized by the fact that the created illumination varies depending on the time of day, year, weather. As a criterion for evaluating the nature of lighting, the coefficient was taken. Natural Illumination KEO. KEO - the ratio of illumination at a given point inside the room to the simultaneous value of the external horizontal illumination created by the light of a completely open sky, expressed as a percentage.
KEO \u003d Evn pom * 100% / E simultaneously osv in the open area
With one-sided side lighting, according to SNiP11-4-79, the minimum KEO value is normalized at a point located at a distance of 1 m from the wall, the furthest from the light openings, at the intersection of the vertical plane of the characteristic section of the room and the conditional working surface (or floor).
With bilateral side lighting, the minimum KEO value is normalized at a point in the middle of the room at the intersection of the vertical plane of the characteristic section of the room and the conditional working surface (or floor).
At the top or top with lateral natural lighting, the average KEO value is normalized at points located at the intersection of the vertical plane of the characteristic section of the room and the conditional working surface (or floor). The first and last points are taken at a distance of 1 m from the surface of walls or partitions.
It is customary to normalize the minimum illumination on a darker section of the working surface. This takes into account: the accuracy of visual work, the reflection coefficient of the working surface and the contrast of the object of distinction with the background. The accuracy of the work is determined by the smallest size (in mm) of the object of distinction, which is taken as the object, its part or defect, distinguishable during operation (risk, crack, line in the drawing).
If the work is associated with an increased risk of injury or intense visual work is performed throughout the working day, then the illumination standards are increased by one step according to the illumination scale (see clause 1.3. SNiP).
In rooms where work of low and very low accuracy is performed, with a short stay of people or in the presence of equipment that does not require constant maintenance, the illumination standards are reduced by one step.
The quality is also standardized. indicators: blindness, discomfort and radiation pulsation, characterizing. light from shiny sources, uneven. the distribution of brightness in the field of view and the change in the brightness of illumination (fluorescent lamps). Combined lighting is allowed when, under the condition of technology or organization of production, as well as under the condition of planning, it is impossible to ensure normalization. the value of KEO, with the exception of residential kitchens, classrooms, etc. As artificial. lighting in this case isp-Xia gas discharge. lamps. Direct solar. rays in large doses are harmful: they cause glare and increase the air temperature in rooms, heat up equipment.
All this leads to visual fatigue, loss of orientation, reduced productivity, accidents, and injuries. Therefore, in industrial premises (II-V climatic regions), sun protection devices (blinds, curtains) are provided.
9. Methodology for calculating natural consecration
Natural lighting is created by sunlight through skylights. It depends on many objective factors, such as: time of year and day, weather, geographic location, etc. The main characteristic of natural lighting is the coefficient of natural light (KEO), that is, the ratio of natural light inside the building Ev to the simultaneously measured outdoor light horizontal surface (En). KEO is denoted by "e":
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The higher the level of visual work, the less uneven illumination is allowed.
To determine the required areas of light openings, the following dependencies are used:
For side lighting (window area):
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where Sp - floor area, m2;
en - normalized value of KEO;
ho, hf - light characteristic of windows and lanterns, respectively;
K is the coefficient for taking into account the shading of windows by opposite buildings;
r1, r2 - coefficients that take into account the increase in KEO in side and top lighting due to light reflected from the surfaces of the room;
τо is the total coefficient of light transmission of light apertures.
The KEO calculation is based on its dependence on the direct light of the sky and the light reflected from the surfaces of buildings and premises. So, with side lighting eδ = (Eδq + E3qK) τоr, where: Eδ, E3q - geometric coefficients of illumination from the sky and the opposite building; q is the coefficient for taking into account the uneven brightness of the sky; K is the coefficient for taking into account the relative brightness of the opposing building; τо - coefficient of light transmission of light apertures; coefficient for taking into account the growth of KEO due to the reflection of light from the surfaces of the room.
The geometric coefficients of illumination are determined graphically according to the Danilyuk method by counting the number of participants (sectors) of the sky visible in the light aperture in the vertical and horizontal planes.
KEO is determined for the characteristic points of the room. With one-sided side lighting, a point located at a distance of 1 m from the wall, the furthest from the light openings, is taken. With two-sided side lighting, KEO is determined at a point in the middle of the room.
10. Control of lighting in production conditions, devices used.
To create favorable working conditions, rational lighting is important. Insufficient lighting in the workplace makes it difficult to carry out work, reduces labor productivity and can be the cause of accidental accidents.
For a room with computers:
1. A large contrast should be avoided between the brightness of the screen and the surrounding space (luminance meter device). It is forbidden to work in a dark / semi-dark room. Lighting should be mixed (natural + artificial)
2. Illumination on the surface of the table in the area where the working document is placed should be from 300-500 lux. (luxmeter)
3. In addition to general lighting, local lamps are used. They should not create glare on the surface of the screen, should increase the illumination of the screen > 300 lux.
Operation includes: regular cleaning of glazed openings and fixtures from dirt; timely replacement of burnt out lamps; network voltage control; regular repair of lamp fittings; regular cosmetic repairs of the premises. For this, special mobile carts with platforms, telescopic ladders, suspension devices are provided. All manipulations are performed with the power off. If the suspension height is up to 5 m, they are served by ladders with stepladders (2 people are required). Lighting control is carried out at least once a year by measuring the illumination or light intensity using a photometer; subsequent comparison with the standards. Control devices: Luxmeter Yu-16, Yu-17
11. Influence of consecration on labor safety and its productivity.
Requirements for rational lighting production. premises are as follows:
the right choice of light sources and lighting systems;
creation of the necessary level of illumination of working surfaces;
limiting the blinding effect of light;
elimination of glare, ensuring uniform illumination;
limiting or eliminating fluctuations in the luminous flux over time.
With insufficient illumination and eye strain, the state of visual functions is at a low functional level, as a result, visual fatigue develops, overall working capacity and labor productivity decrease, and the number of errors increases.
Illumination in the workplace when working with the display should be 200 lux, and in combination with working with documents - 400 lux.
Soft scattered is applied. light from several sources, light coloring of the ceiling, walls and equipment. Convenient direction is artificial. light is considered from the top left and a little behind
To reduce glare from the monitor screen, which hinders the work of the operator, it is necessary to use screen filters that increase image contrast and reduce glare, or monitors with anti-glare coatings.
An important task is the choice of the type of lighting (natural or artificial). The use of natural light has several disadvantages:
the flow of light, as a rule, only from one side;
uneven illumination in time and space;
blinding in bright sunlight, etc.
The use of artificial lighting helps to avoid the above disadvantages and create an optimal light regime.
12. Emergency consecration.
emergency- lighting, providing for the provision of minimum illumination in the event of a blackout of the working lighting and the associated violation of the normal maintenance of the equipment. It must be powered by its own source. Can go offline. The minimum illumination of working surfaces with emergency lighting should be 5% of the normalized illumination of working lighting, but not less than 2 lux.
A distinction is made between emergency or auxiliary lighting on the one hand, and emergency lighting on the other.
Emergency lighting takes over the functions of general lighting in the event of a power outage and provides thus. further basic work. Basically, in these cases, spare power generators are used, which supply electricity to the same lamps. A minimum of 10% of the normal recommended illumination for the activity should be guaranteed.
Emergency lighting is divided into:
Lighting for rescue routes; a minimum illumination of 1 lux for every 0.2 m of height von >1lx in 0.2 m Hohe is required to be able to safely leave the premises, with a uniformity of 1:40.
Anti-panic lighting as the minimum basic lighting that makes it possible to easily reach emergency exits from large rooms.
Lighting for especially dangerous workplaces (near machines with moving parts) where, in the event of a lighting failure, there is an immediate danger of an accident and a danger to the life of workers.
13. The impact of infrared and ultraviolet radiation on the human body and methods of protection against them.
light emission are electromagnetic oscillations in the optical region of the spectrum; along with the visible part, it gives an invisible ultraviolet (wavelength 0.1 - 0.38 microns) and infrared (0.78-3.4 microns). ultraviolet radiation is a carrier of mainly chemical energy, infrared- thermal.
ultraviolet radiation have a biologically positive effect on the human body, at the same time causing darkening of the skin - an erative effect (tanning).
However, at high intensities, UV can cause skin burns, retinal burns, which can lead to loss of vision. UV radiation occurs during: the operation of quartz lamps, an electric arc, the operation of laser installations, electric and gas welding.
UV protection - clothing, fabric, goggles with regular glass.
Infrared radiation It is manifested mainly by their thermal effects and, with prolonged exposure, can cause heat stroke and sunstroke.
Sources of thermal radiation in industry - flame furnaces, steam pipelines, heat units.
Thermal Radiation Protection:
Elimination of heat sources;
Shielding (reflecting screens made of brick, aluminum, tin, asbestos);
Absorbing screens (water and chain curtains);
Personal protection (overalls, felt hats, heat-resistant shoes and gloves, blue glass goggles).
14. Noises. Basic protection measures
Noises and vibrations adversely affect human health, causing prof. diseases.
Noise- random combination of sounds is different. frequency and intensity arose. with fur. vibrations in an elastic medium. The medium can be solid, liquid, gaseous. Noises are therefore fur-mi, hydro-noises, air, aerodynamic. Duration Noise exposure: decreased hearing, visual acuity. The blood is reduced. pressure, suffers from the central nervous system. Increased number of errors, which leads to accidents. We perceive with the organs of hearing. sounds: 20Hz-20kHz.
· <20Гц – инфразвуки
>20kHz – ultrasounds
Also a biologist. impact on the human body. With sound. fluctuations of the particles of the medium arose. change. pressure, N/m2.
Spreading sound. waves are accompanied by energy transfer, the value of kt is determined by the intensity of sound. Intensity - the number E carried by the sound. wave in unit area, normal to, for example. wave propagation in a unit of time. I=p2/ρ*c, W/m2.
p - Sound. pressure, Pa
ρ – density, kg/m3
ρ * s - wave resistance
s is the speed of sound in the medium, m/s
Min. p0 and I0, distinguished by people as a sound, called. hearing threshold.
To assess noise, they use not abs. intensity and p values, and their relative levels in the logarithm. units taken with respect to the threshold p0 and 0I. Measured in decibels.
Noise level is normalized:
LI=10 lg I/I0 Lp=20 lg p/p0
top. Threshold I: 150dB.
Engineering Methods: low frequency noises<400Гц
medium frequency Hz
high frequency >1000Hz
Noise regulation.
Rationing of noise levels in production conditions is carried out in accordance with GOST 12.1.003-83 (noise, general safety requirements). It establishes permissible levels of sound pressure dB at workplaces in certain (octave) frequency bands with geometric mean frequencies of 63,125,250,500,1000,2000,4000,8000 Hz. For example, workplaces in industrial premises, respectively: 99.92.86.83.78.76.74 dB or 85 dBA.
The geometric mean octave (one-third octave) frequency band is determined by:
f(av) = f(n)*f(c), where
f(n), f(v) - lower and upper cutoff frequencies, for octave bands f(v)/f(n)=2, for one-third octaves f(v)/f(n)=1.26.
Hygienic standards defined by GOST. There are sanitary standards for residential and general. buildings. Noise in the workplace is regulated in 2 ways: basic– rationing
According to a separate noise spectrum. Let's normalize. sound levels. pressure in 8 octave bands. For kzh octaves / frequency bands with its environments. geometer. frequency. is determined admissible. sound level. pressure depending on the performance. works, from exposure time
By the nature of the noise spectrum- broadband, tonal.
In time, the noise is characterized as constant and non-constant (intermittent, impulsive).
Solasno other method for an indicative assessment, the equivalent sound level measured in dB "A" is taken as a characteristic of noise at workplaces: ШВ-1, ШВ-2.
Sound level meter - speaker device, pointer device, def. by sound. pressure. There is an "A" scale for obtaining results in dB "A". The sound level meter set includes band-pass, three-octave filters.
For sanitary hygiene. assessments of the use of ShVK (noise-vibration complex).
In the room where workers work, the level should not exceed 60 dB "A", where the units are installed - 75 dB "A".
To reduce noise in industrial premises, the following measures are taken:
· reduction of noise level in ist. its occurrence
sound absorption and soundproofing
Installation of silencers (active and reactive)
Rational placement of equipment
PPE: anti-noise headphones, helmets, liners, plug.
Noise, vibration and ultrasound are vibrations of material particles of a gas, liquid or solid. Production processes are often accompanied by significant noise, vibration and shaking, which adversely affect health and can cause occupational diseases.
The human hearing aid is not the same. different sensitivity to sounds. frequencies, the greatest sensitivity at medium and high frequencies (Hz) and the smallest - at low (20-100 Hz). Therefore, for physiological The noise estimates use curves of equal loudness (Fig.30) obtained. according to the results of studying the properties of the organ of hearing, evaluate sounds differently. frequency by subjective. a sense of loudness, that is, to judge which of them is stronger or weaker.
Loudness levels are measured in phons. At a frequency of 1000 Hz, the volume levels are taken equal to the sound pressure levels. According to the nature of the noise spectrum, they are divided into:
broadband: spectrum > one octave (an octave when f (n) differs from f (k) by 2 times).
tonal - one or more tones are heard.
By time, the noise is divided into constant. (level over 8 hours working day does not change > 5 dB).
Fickle(the level changes over 8 hours of the working day by at least 5 dB).
The inconstant are divided: hesitating. in time - constantly changing over time; intermittent - abruptly interrupted with an interval of 1 s. and more; pulse - signals with a duration of less than 1 s.
Any increase in noise above the threshold of hearing increases muscle tension, which means it increases the expenditure of muscle energy.
Under the influence of noise, visual acuity is dulled, the rhythms of respiration and cardiac activity change, there is a decrease in working capacity, weakening of attention. In addition, noise causes increased irritability and nervousness.
Tonal (a certain noise tone dominates) and impulse (intermittent) noise are more harmful to human health than broadband noise. The duration of exposure to noise leads to deafness, especially when the level exceeds 85-90 dB, and first of all, sensitivity at high frequencies decreases.
If it is impossible to reduce the noise to the normative by the above methods, personal protective equipment is used - noise suppressors. Noise suppressors according to GOST 12.4.011-75 are divided into three types:
- earmuffs covering the auricle;
- liners covering the external auditory canal (cork);
- helmets covering part of the head and auricle
Headphones according to the method of attachment to the head are divided into:
independent (with a headband);
Vibration damping (installation of vibrators on vibration-damping foundations)
· signaling
dosimetric control is required
4 methods embedded in the devices:
ionization control method
suintillation (emission of photons visible light when AI passes through it);
photographic method
chemical method - discoloration, sediment, decomposition, etc.
Dosimetric control:
1) for radiation reconnaissance of the area - a radiometer-radiometer;
2) to control exposure - dosimeters;
3) to control the degree of contamination of the surface of substances, food
Wed ind. protection:
Dressing gowns, overalls, apron, trousers, armlets, gloves, gas masks, goggles, special footwear, cases, radio protectors.
The quantitative characteristic of X-ray and gamma radiation is the exposure dose - X-ray C/kg. The nature and severity of damage to the body depends on the amount of absorbed radiation dose - rad (J / kg).
Since different types of radiation with the same absorbed dose cause different consequences, the concept of rem (biological equivalent of X-ray) has been introduced to assess the radiation hazard.
The new unit of equivalent dose in the SI system of units is Sievert, 1 Sv = 100 rem.
1. Basic lighting engineering. parameters that determine the visual conditions of work .... ... ... 1
2. requirements for industrial lighting ............................................... ................... 1
3. Types and systems of industrial lighting ............................................... ................ 1
4. Rationing of artificial lighting .............................................. ....................... 2
5. Sources of artificial light............................................... ............................................... 3
6. Classification of luminaires.............................................. ................................................... 3
7. Methods for calculating artificial lighting .................................................... ...................... 4
8. Rationing of natural light ............................................................... ......................... 5
9. Methodology for calculating natural sanctification .............................................. ................... 6
10. Control of lighting in production conditions, devices used .......... 7
11. The impact of consecration on labor safety and productivity .............................................. 7
12. Emergency consecration.................................................... ................................................. .... 8
13. Influence of infrared and ultraviolet radiation and methods of protection against them. 8
14. Noises. Basic protective measures ............................................................... ..................................... 9
15. Vibration............................................... ................................................. ..................... eleven
16. The effect of vibration on a person, sanitary-hygienic and technical. normalization: 11
17. General methods for dealing with the harmful effects of vibration: .............................................. 12
18. Vibration isolation of machines.............................................. ................................................. 13
19. Personal protective equipment against the harmful effects of vibration .................................... 13
20. Vibration measurement and vibration measuring equipment .............................................................. 14
21. Measures to reduce vibration and the source of their occurrence .................................... 14
22. Electromagnetic fields. safety requirements with EM radiation sources 15
23. Ionizing radiation............................................................... ............................................ 16
Professional lighting technicians and specialists working in the field of lighting constantly use different terms and definitions that mean little to the average layman.
To make it easier to understand what in question, and what these words mean, we have prepared a list explaining the main lighting terms and characteristics. It does not need to be learned by heart, you can simply go to the desired page and refresh the forgotten parameter in your memory. Speaking "in the same language" is always easier.
Lighting parameters and concepts.
1 - Visible and optical radiation
The entire world around us is formed by visible radiation concentrated in the band of electromagnetic waves from 380 to 760 nm. Ultraviolet radiation (UV) is added to it on one side, and infrared (IR) on the other.
UV rays have a biological effect and are used to kill bacteria. Dosed they are used for therapeutic and healing effects.
IR rays are used for heating and drying in installations, as they mainly produce a thermal effect.
2 - Luminous flux (F)
The luminous flux characterizes the power of visible radiation by its effect on human vision. measured in lumens(lm). The value is independent of direction. Luminous flux is the most important characteristic.
For example, an E27 75 W incandescent lamp has a luminous flux of 935 lm, a 75 W halogen G9 - 1100 lm, a 35 W T5 fluorescent lamp - 3300 lm, a 70 W metal halide G12 (warm) - 5300 lm, an E27 LED 9.5 W ( warm) - 800 lm.
3 - Lumen
Lumen (lm) is the luminous flux from a light source (lamp) at an ambient temperature of 25°, measured under reference conditions.
4 - Illumination (E)
Illumination is the ratio of the luminous flux supplied to a surface element to the area of this element. E \u003d F / A, where, A is the area. Illumination unit - luxury(OK).
Most often, horizontal illumination is normalized (on a horizontal plane).
Average ranges of illumination: outdoors under artificial lighting from 0 to 20 lux, indoors from 20 to 5000 lux, 0.2 lux during the full moon in natural conditions, 5000-10000 lux during the day with cloudy conditions and up to 100,000 lux on a clear day.
The picture shows: a - the average illumination on the area A, b - the general formula for calculating the illumination.
5 - Strength of light (I)
The intensity of light is the spatial density of the luminous flux limited by a solid angle. That is, the ratio of the light flux emanating from a light source and propagating inside a small solid angle containing the direction under consideration.
I \u003d F / ω The unit of measurement of luminous intensity is candela (cd).
The average luminous intensity of a 100 W incandescent lamp is about 100 cd.
KSS ( light intensity curve) - the distribution of luminous intensity in space, this is one of the most important characteristics of lighting devices, necessary for calculating lighting.
6 - Brightness (L)
Brightness (light density) is the ratio of the luminous flux carried in an elementary beam of rays and propagating in a solid angle to the cross-sectional area of a given beam.
L=I/A (L=I/Cosα) Luminance unit - cd/m2.
Brightness is related to the level of visual sensation; The distribution of brightness in the field of view (indoors/interiors) characterizes the quality (visual comfort) of lighting.
In complete darkness, a person reacts to a brightness of one millionth of a cd / m2.
A fully luminous ceiling with a brightness of more than 500 cd / m2 causes discomfort in a person.
The brightness of the sun is about a billion cd/m2, and that of a fluorescent lamp is 5000-11000 cd/m2.
7 - Light output (H)
The luminous efficacy of a light source is the ratio of the luminous flux of a lamp to its power.
Η=F/R The unit of measure for light output is lm/W.
This is a characteristic of the energy efficiency of the light source. Lamps with high luminous efficiency provide energy savings. Replacing an incandescent lamp with a light output of 7–22 lm/W with fluorescent ones (50–90 lm/W), the power consumption will decrease by 5–6 times, and the illumination level will remain the same.
8 - Color temperature (TC)
Color temperature determines the color of light sources and the color tone of the illuminated space. The color temperature is equal to the temperature of a heated body (Planck emitter, black body), the same color as a given light source.
The unit of measurement is Kelvin (K) on the Kelvin scale: T - (degrees Celsius + 273) K.
Candle flame - 1900 K
Incandescent lamp - 2500–3000 K
Fluorescent lamps - 2700 - 6500 K
Sun - 5000–6000 K
Cloudy sky - 6000–7000 K
Clear day - 10,000 - 20,000 K.
The color rendering index characterizes the degree of reproduction of the colors of various materials when illuminated by a light source (lamp) when compared with a reference source.
The maximum value of the color rendering index is Ra =100.
Color Rendering Ratings:
Ra = 90 or more - very good (color rendering 1A)
Ra = 80–89 - very good (color rendering 1B)
Ra \u003d 70–79 - good (color rendering degree 2A)
Ra \u003d 60–69 - satisfactory (color rendering degree 2B)
Ra \u003d 40–59 - sufficient (color rendering degree 3)
Ra = less than 39 - low (color rendering 3)
Ra he is CRI- The color rendering index was designed to compare continuous spectrum light sources whose color rendering index was greater than 90, since below 90 it is possible to have two light sources with the same color rendering index but with very different color rendering.
Comfortable for the human eye CRI value = 80–100 Ra
There are such lighting devices, which streams of light distribute from sources to where it is required. They are called Lighting Devices (OL) and are divided into lamps, spotlights and projectors.
The lamps include those OPs that spread the flow of light from the source not far. Therefore, objects that are nearby from these light sources, at a close distance, are illuminated. Lamps used to illuminate something inside and outside the room.
For a simple calculation of the required number of lamps, use the Lamp Quantity Calculator.
Spotlights emit light from a source at a narrow illumination angle. This allows you to clearly illuminate objects that are at a great distance and large sizes. Spotlights illuminate objects on the street.
For projectors, the purpose is not only to illuminate the surface, but also to transfer an image to this surface. A prime example is a movie projector. It illuminates a well-defined area from a given space. With the help of optical systems, the projector uniformly illuminates the required surface and creates on this surface a clear image of various scales from one place to another.
Lighting fixture settings.
First lamp characteristics are the light intensity curves. The distribution of the light flux determines its purpose. And the distribution of the luminous flux in space is estimated using the luminous intensity curve. The luminous intensity curve is displayed as a graph I (a,b). A and b are the angles of propagation of the light flux in the longitudinal and transverse planes. The larger the oval from the light stream, the narrower the curved light intensity and the higher the illumination in the center of the light spot. This is an important indicator of a light fixture.
According to typical light intensity curves, 7 types of OP are distinguished: concentrated (K), deep (D), cosine (D), semi-wide (L), wide (W), uniform (M), sine (S). Typical luminous intensity curves (in cd) of a luminaire are calculated for the value of luminous intensity with a lamp luminous flux Fcv = 1000 lm. The main feature that determines the type of curve is the ratio of the maximum lamp luminous intensity to the arithmetic mean for the given plane.
The second lighting characteristic is the ratio of flows emitted into the lower and upper hemispheres. Depending on this, light fixtures are divided into classes, depending on what proportion of the total lamp flux is the luminous flux of the lower hemisphere. The flow in space can be distributed predominantly downward ( direct light fixtures), mostly up ( reflected light fixtures), uniformly in all directions ( diffused light fixtures).
Ambient light fixtures are better suited for general room lighting as they give an even distribution of brightness. Sufficient light saturation ensures visual comfort.
Reflected light fixtures provide comfortable and uniform lighting, as they fully comply with the norms for limiting glare and discomfort. They saturate the space with light, combining well with overhead or side daylight.
Direct light fixtures are used for rooms with low ceilings. These are ceiling-mounted or built-in appliances. They are economical, highlight the right place, are used to highlight paintings, objects, sculptures.
Lighting devices are divided into 5 classes, depending on the size of the luminous flux incident on the lower hemisphere: direct light (share 80% - P), predominantly direct (60-80% -H), diffused (40-60% -P), predominantly reflected (20-405-B), reflected (less than 20% -O). These parameters can be found in the accompanying documents on the OP.
important lighting characteristic OP is the efficiency factor. According to their main purpose, lighting fixtures are divided into groups. For lighting industrial premises, administrative, office and other public premises, agricultural premises, sports facilities; for functional and decorative outdoor lighting; for internal lighting of means of transport and for architectural and artistic lighting of buildings, structures, monuments, fountains, etc., as well as for emergency lighting.
This classification is conditional, since the same lamp can be used in different situations.
Op differ in constructive application and installation method. According to GOST17677, there are built-in (B), ceiling (P), suspended (C), wall (B), floor (H), crowning (T), cantilever (K), portable (P). The design feature of the lamp sets its position in space to obtain the best effect.
Luminaires for any purpose is artificial lighting. Today, a huge role is given to artificial lighting. With this lighting, a person spends most of his life. People also use lighting devices in the daytime. Today, artificial light is no longer just lighting. It also became a lighting design in the overall interior. At night, the cities sparkle with various types of lighting fixtures. Therefore, it is very important to know the features and characteristics of lighting devices so as not to harm human health and reasonably save electrical energy.
Light flow F – the power of radiant energy, estimated by the visual sensation it produces, lumen (lm).
Light Force I is the spatial density of the light flux:
Ia=d F/ dω,
Where dФ - luminous flux (lm), evenly distributed inside the elementary solid angle dω, sr (steradian). The unit of measurement for luminous intensity is the candela (cd), equal to the luminous flux
In 1 lm, propagating inside a solid angle in 1 sr.
illumination– surface luminous flux density, lux (lx):
E= d F/ ds,
Where dS- surface area, m 2, on which the luminous flux falls d F.
Brightness B is the surface density of light intensity in a given direction. Brightness, which is a characteristic of luminous bodies, is equal to the ratio of the luminous intensity in a given direction to the projection area of a luminous surface onto a plane perpendicular to a given direction:
B=I/ dS cosα,
Where I is the intensity of light in a given direction, cd; dS is the area of the radiating surface, m2; α is the angle between the radiation direction and the plane, deg. The unit of measurement of brightness is cd / m 2.
What is a lamp?
What is the function of lighting fittings in a lamp?
What is the design of artificial lighting? Why is it forbidden to use one local lighting?
The use of one local lighting in industrial premises is prohibited, since a sharp contrast between brightly lit and unlit places leads to eye strain, slows down the speed of work and can cause accidents.
What is General Lighting? What are some ways to increase the illumination created by general lighting?
What is Composite Lighting? In what cases does it apply?
What are the advantages of incandescent lamps over gas discharge lamps?
The main advantage of gas discharge lamps over incandescent lamps is their high light output from 40 to 110 lm/W. They have a much longer service life - over 10 thousand hours, low temperature surface of the lamp, a spectrum of radiation close to sunlight, providing high quality color reproduction. In addition, gas discharge fluorescent lamps provide more uniform illumination and are recommended for use in general lighting fixtures.
What is the principle of operation of lamps used in classrooms? What are the advantages of these lamps?
Causing in a gaseous electrical discharge, into visible light.
Fluorescent lamps, depending on the phosphor used in them, create a different spectral composition of light and are white (LB), warm white (LTB) and cold white light (LHB), daylight (LD), color corrected daylight (LDC).
What are the disadvantages of gas discharge lamps?
The disadvantages of gas-discharge lamps should also include: the need to use special starting devices, the dependence of the lamp's performance on the ambient temperature and the magnitude of the supply voltage, a long warm-up period for high-pressure lamps (10 - 15 minutes).
What is the ripple factor of illumination?
TO P = 100 (E Max – E min) / 2 E Wed where E Max, E min and E cp - the maximum, minimum and average value of illumination for the period of its fluctuation, lx.
The value of the pulsation coefficient of illumination varies from a few percent (for incandescent lamps) to several tens of percent (for gas-discharge lamps).
What is the reason for the pulsation of the luminous flux of light sources? Which type of lamp has the highest flicker factor?
The luminous flux of the lamp Ф at the moment of transition of the instantaneous value of the alternating voltage of the network through 0 decreases.
Rice. Pulsations of the light flux at a single-phase supply voltage
Discharge lamps (including fluorescent ones) have low inertia and change their luminous flux Ф almost in proportion to the amplitude of the mains voltage. The large thermal inertia of the filament of incandescent lamps prevents a noticeable decrease in the luminous flux of the lamp.
How can I reduce the ripple factor of illumination?
What is the stroboscopic effect and why is it dangerous?
Permissible values of what indicators of artificial lighting are established by SNiP 23-05-95?
Depending on what factors are the permissible values of artificial lighting indicators established?
What factors determine the characteristics of visual work?
object of distinction
Background- the surface adjacent directly to the object of distinction, on which the object is considered. The background is characterized by a reflection coefficient that depends on the color and texture of the surface. The reflection coefficient ρ is defined as the ratio of the light flux reflected from the surface Ф neg to the light flux incident on it Ф pad. The background is considered light when the reflectance of the surface on which the object is viewed is more than 0.4; medium - with a reflection coefficient from 0.2 to 0.4; dark - with a reflection coefficient of less than 0.2.
The contrast of the object of distinction with the background K is determined by the ratio of the absolute value of the difference in the brightness of the object of distinction IN o and background IN f to the largest of these two brightnesses. The contrast is considered large at values TO more than 0.5; average - at values TO from 0.2 to 0.5; small - at values TO less than 0.2.
What is an object of distinction? Give examples.
According to what characteristic, obtained in the calculation of illumination, is the light source selected? What parameters of the lamp need to be determined?
The required luminous flux of the lamp Ф is calculated, which provides the normalized illumination value in the room E, and according to the lighting reference book, the type and power of a standard lamp with a luminous flux Ф GOST, close in magnitude to the calculated one, is selected.