By purchasing lighting equipment, we are curiously reading the light parameters specified in the characteristics. Color temperature, illumination, luminous flux - for some of us the full importance and physical significance of these parameters in illumination is not fully understood. But what information useful for us and our budget is behind these figures. Let's try to clarify: what are these or those characteristics, and how to choose a really high-quality lamp or lamp.
Basic physical parameters.
Light flow.
The luminous flux is an important characteristic of a light source. This is a physical quantity characterizing the amount of visible light power in the radiation flux of a lamp or lamp. By visible light is meant the radiation flux perceived by the human eye, which has an average sensitivity. From this definition it is obvious that not everyone can see the radiation of a light source, but the more he sees, the greater the light flux. The unit of measurement of the entire perceived luminous flux is lumen.
Interestingly, human vision perceives different colors in different ways, even if they are radiated with the same power. A bell-shaped curve showing the color sensitivity of the eye is called the spectral efficiency of the light flux. According to her, the green light (wavelength of 550 nm) is perceived as brightest, weakening to the red and blue edges of the spectrum. In other words, with the emission of green and blue light sources having the same power, green light produces more light flux than blue. Thus, the lumens show real values visible to the eye, unlike the Watts.
The range of LED lamps and Shine® luminaires allows you to choose light sources with a light output of 75 lm, as for example in miniature decorative lamps of the G4 series, up to 26 600 lm, as in LED street lamps.
Illumination.
The luminous flux is not the only parameter that characterizes the possibilities of the lighting device. To evaluate the characteristics of LED lighting and compare them with traditional light sources, instead of the term "light flux", the term "illumination" is often used. Illuminance characterizes the intensity of light falling on the surface, or rather the amount of light from the lighting device that reaches the illuminated area. This is the part of the light flux that is effectively directed to the work surface. Unit of measurement of illumination is lux - a physical quantity equal to the luminous flux of 1 lumen per 1 square meter. Below are examples of illumination from various light sources.
Fig. 2. Table of values of illumination under different conditions.
| Description | Illumination, lux |
| Outside the atmosphere at an average distance from the Earth to the Sun. | 135 000 |
| The greatest solar illumination with a clear sky | 100 000 |
| Normal illumination in the summer at noon in the middle latitudes | 17 000 |
| In cloudy weather in the summer at noon | 12 000 |
| When filming in the studio | 10 000 |
| Normal illumination in the winter in the middle latitudes | 5 000 |
| On the football field (artificial lighting) | 1 200 |
| In the open on a cloudy day | 1 000 - 2 000 |
| Sunrise and sunset in clear weather | 1 000 |
| In a bright room near the window | 800 |
| On the desktop for fine work | 400 - 500 |
| On the screen of the cinema | 85 - 120 |
| Necessary for reading | 30 - 50 |
| In the sea at a depth of 50 - 60 m | up to 20 |
| Full moon night | 0,2 |
| On a moonless night | 0,001 - 0,002 |
| On a moonless night with a continuous cloudiness | up to 0,002 |
As can be seen, in order to provide favorable conditions, an illumination of about 400-800 lux is needed. You can provide such illumination in two ways: either by a powerful light source or by a large number of lighting devices. By selecting LED lamps and Shine® lamps, you choose reliable and powerful sources light with minimal energy consumption.
Light feedback.
The indicator of efficiency and profitability of light sources is light output (or light output). The light output of a light source is the ratio of the light flux emitted by the source to the power consumed by it. In the international system of units is measured in lm / W. Different light sources have different light output. According to the table below, the most economical are LED and fluorescent lamps.
Fig. 3. A table of values of the light output of different sources
Light output lED Light Fixtures S hine® is one of the best products in its class and reaches 98.4 lm / W.
Color rendering index.
The color rendering index reflects the ability of a light source to correctly transmit colors of various objects in comparison with an ideal light source. This parameter is a quantitative indicator of the quality of reproduction of color shades on a scale from 0 to 100. By definition, the color rendering index of sunlight is 100.
The minimum acceptable value of the color rendering index of a light source depends on the area of its application:
1. The value of the color rendering index in the range from 80 to 90 is required in trade and industrial premises, in which accurate color rendition is critically important - for example, in stores selling fabrics, works of art, or in art studios.
2. For most office, retail, educational, medical and other work and living quarters, the color rendering index must be at least 70-80.
3. In industrial, security and warehouses, where accurate color rendering does not matter much, light sources with a small color rendering index of less than 70 can be used.
LED and compact fluorescent lamps Shine® meet the highest requirements for color reproduction and can be used in rooms with any requirements for lighting.
Colorful temperature.
 |
| Fig. 4. Color temperature of light sources. |
The color temperature characterizes the visible color of the source, and is also the basis of the objectivity of the impression of the color of the surrounding objects.
800 K - the beginning of the visible dark red glow of the red-hot bodies;
1500-2000 K - candle flame light;
2000 K - high pressure sodium lamp;
2200 K - incandescent lamp 40 W;
2680 K - incandescent lamp 60 W;
2800 K - incandescent lamp of 100 W;
3000 K - incandescent lamp 200 W, halogen lamp;
3400 K - the sun at the horizon;
4300-4500 K - morning sun and sun at lunch time;
4500-5000 К - xenon lamp, electric arc (welding);
5000 K - The sun at noon;
5500 K - clouds at noon;
5500-5600 K - flash;
6500-7500 К - cloudiness;
7500 K - daylight, with a large fraction of the scattered from a clear blue sky;
7500-8500 К - twilight;
9500 K - blue cloudless sky on the north side before sunrise;
10000 К - light source with "infinite temperature", used in aquariums (shade of blue color);
15000 K - clear blue sky in winter;
20000 K - blue sky in the polar latitudes.
LED lamp and Shine® lamps are available with a color temperature of 2700 K to 6500 K. Thus, you can choose a light source for various purposes or simply to your taste. Whether it is a "warm" home environment, a working "cool" office lighting or a "cold" office that gives clear outlines of objects, street lighting - Shine® light sources are guaranteed to provide the desired shade of light and level of illumination.
We have tried to acquaint you only with the basic physical quantities, which operate with a qualitative evaluation of the light of the lighting devices. There is a mass of other derived parameters that are responsible for this or that aspect of the lamp or lamp operation. But, already having an idea of the basic characteristics, you can easily independently analyze the proposed lighting equipment and choose the best option. In turn, specialists of our company are always ready to give full information on all Shine® products meeting the highest requirements.
The main normalized indicators are the illumination at the workplace, the general color rendering index, the light ripple coefficient. For all workplaces indoors and for workplaces outside the premises where concrete work is performed (railway stations, airports, quarries, etc.), the main normed value is illumination at the workplace. The magnitude of the normalized illumination depends, first of all, on the nature of the work performed.
When lighting streets and roads, the normalized value is the brightness of the road surface. It is established depending on the category of persons, traffic intensity, the nature of the surrounding situation.
The overall color rendering index is the ratio of the reproduction of the colors of objects when they are illuminated by this light source to reproduce the colors of the same objects illuminated by the light source adopted for the standard. For the "standard" source, the light of the thermal radiators, incandescent lamps was taken - their total color rendering index was assumed equal to 100. The following color quality estimation system was adopted:
Ra\u003e 90 - excellent quality;
90\u003e Ra\u003e 80 - very good;
80\u003e Ra\u003e 70 - good;
70\u003e Ra\u003e 60 - satisfactory;
60\u003e Ra\u003e 40 - acceptable;
For example, Russian standards for lighting have established that for a printing, textile, paint and varnish industries, as well as for surgical departments of hospitals, the overall color rendering index should be at least 90.
In Russia, the light-pulsation coefficient is also normalized. In gas-discharge light sources - luminescent, metal halide, sodium lamps - the amount of light flux varies with a doubled frequency of the network current. In Russia, the United States, CIS countries, Europe and Asia, the frequency of alternating current in electrical networks is 50 Hz. Consequently, the light flux of the lamps changes ("pulsates") 100 or 120 times per second - all the gas-discharge lamps seem to flicker at this frequency. The eye of these flickers does not notice, but they are perceived by the body and at a subconscious level can cause unpleasant phenomena - increased fatigue, headache, possibly stress. In addition, when a pulsating light is illuminated by rotating or vibrating objects, a so-called "stroboscopic effect" occurs, when when the frequency of rotation or vibration coincides with the frequency of pulsations of light, the objects appear to be stationary, and when incomplete coincidence, they rotate at very low speeds. This causes people to erroneous reactions and is one of the major causes of injuries in the workplace.
The depth of pulsations is measured by the coefficient of pulsation of illumination. In the Russian standards it is established that the depth of pulsation of illumination at workplaces should not exceed 20%, and for some types of production - 15%.
In Russia, the main document setting the parameters of lighting are Building Norms and Rules SNiP 23-05-95. In addition to these norms, there are Sanitary Rules and Norms of SanPiN 2.21 / 2.1.1.1278-03, Moscow City Building Standards MGSN 2.06-99 and many industry norms.
In Europe, there are common European standards of illumination, several dozens of specialized norms, as well as many national norms and rules. In the European standards of illumination for a number of rooms, another standard parameter is introduced: for workplaces equipped with monitors (ie practically for all workplaces in offices), the requirements for maximum brightness of those surfaces of luminaires that can be reflected in the screens are established. Here are a number of European standards of illumination:
| Type of premises, occupation | Illumination, lux | The generalized indicator of discomfort UGR | Color rendering index Ra |
|---|---|---|---|
| Wardrobes, walkways, traffic areas | 300 | 19 | 80 |
| Letter, typescript, reading, data processing | 500 | 19 | 80 |
| Technical drawing | 750 | 16 | 80 |
| Jobs for computer design | 500 | 19 | 80 |
| Conference rooms and meeting rooms | 500 | 19 | 80 |
| Reception rooms | 300 | 22 | 80 |
| Archives | 200 | 25 | 80 |
SOURCES OF LIGHT.
All electric light sources can be divided into three groups:
1. Sources of light with a glow body.
1.1. Incandescent lamps
1.2. Halogen lamps
2. Gas discharge lamps
2.1. Low-pressure discharge lamps (fluorescent)
2.2. High-pressure discharge lamps (mercury, sodium, metal halide)
3. Semiconductor light sources - LEDs.
Light sources are usually compared by a number of parameters that determine how much different types lamps are applicable in this or that case.
Lamp power - The electrical power consumed by the lamp. The unit of measurement is watt (W).
Light flow. For example, a conventional incandescent lamp with a power of 100 W can have a luminous flux of 1200 Lm, a halogen lamp of 35 W - 1200 Lm, a sodium lamp with a power of 400 W - 48000 Lm. Those. Different types of lamps have different light output, which determines the conversion efficiency electric power in light, and, therefore, different economic efficiency of application.
Luminous feedback measured in Lm / W (ie every watt of electricity consumed gives some amount of light). The higher the ratio of the light flux to the lamp power, the more efficient is the conversion of the consumed electricity into light. This is the most important parameter of a lamp in terms of energy saving, and the progress of light sources is to a large extent an increase in light output, its approach to theoretical limits.
Power, luminous flux, light output are quantitative characteristics of lamps. In addition, there are parameters that determine the quality of light - colorful temperature and color rendition.
Colorful temperature determines how we see the colors of objects. Depending on the external lighting, the same color will be perceived by the eye a little differently. The color temperature is measured in degrees Kelvin. Conditionally, the light sources are divided into three main groups by the color temperature.
1. Heat-white
2. Neutral white 3 300 - 5 000 K
3. Cold white\u003e 5 000 K.
In residential interiors traditionally used lamps of warm tone (Tsw = 2,700 - 3,000 K). In the light of such lamps, people's faces look most natural. In office interiors more "cold" lamps are used. Lamps with Тцв = 4000 - 4200 К are suitable, for example, for landscape lighting, emphasizing the emerald green of plants, whereas, say, standard halogen lamps with Тцв = 3 000 К for this purpose are too "yellow". A very interesting effect can be given by the thoughtful use of lamps of different spectra. In the light architecture, the information contained in the chromaticity of light is used to organize space: the motorways are traditionally distinguished by the yellow-gold light of sodium lamps, pedestrian spaces - colder light. Similar techniques can be used in the interior.
Color rendition. Perhaps even more important parameter, which, unfortunately, is often overlooked. This concept we already touched upon when we considered the main lighting parameters. The more continuous and uniform the spectrum has a lamp, the more distinct the colors of objects in its light. The main source of light - the Sun - has a continuous spectrum of radiation and the best color rendition, while Tcv varies from 6,000 K at noon to 1,800 K at dawn and dusk hours. Unfortunately, not all lamps can compare with the Sun. If artificial sources of thermal radiation - traditional and halogen incandescent lamps - do not have special problems with color reproduction due to the continuous spectrum, discharge lamps, which have bands and lines in their spectrum, often convey the colors of objects in a rather peculiar way. In the catalogs of lamps, manufacturers generally indicate the overall color rendering index Ra, determined on the basis of an assessment of the quality of color transfer of the 8 reference color samples. Ra of heat lamps is 100 (maximum value), for discharge it ranges from 20 (sodium lamps) to 95 and even 98. True, Ra does not allow to draw a conclusion about the nature of color transfer, and sometimes even can disorient the designer. Thus, fluorescent lamps with a three-band phosphor (Ra = 80) and white LEDs (declared Ra up to 100) have an Ra corresponding to a "good" color rendition. Often they do not pass satisfactory some colors.
The task of the designer (architect), designing this or that interior (exterior), is a careful selection of lamps to ensure the required quality of color and light. Sources of light - one of the most massive goods produced by man. Annually a few billion lamps are produced and consumed, the lion's share of which is still incandescent. Consumption is growing rapidly modern lamps - compact luminescent, sodium, metal halide. Tempting prospects in energy conservation, and in the design of lighting stops promise ultramodern LEDs. The qualitative changes taking place allow us to hope that the sources of light in the new millennium will become an important tool of the architect, designer, just a creative person - the main character of the coming era of design.
Life time - the most important operational parameter of lamps. Distinguish complete (until it burns) and useful (until the light flux falls below a certain limit) the service life.
| Parameter | Incandescence, reflex (mirror) LN | Halogen, halogen low-voltage HLN | Fluorescent, compact fluorescent LL, CLL | Gas-discharge (metal-halogen) IPF | Gas-discharge (mercury, sodium) DRL, DNA | LED Light LED |
|---|---|---|---|---|---|---|
| Colorful temperature | 2 700 K - warm ("Yellow") light |
3 000 K - white (neutral) light, the spectrum is closer to solar |
2 700K - warm light; 2 900K ... 4 000K - white light; 5 400K ... 6 400K - cold light. |
3 000 K ... 4 200K - white (neutral) light, spectrum closer to solar |
2 000K ... 2 700K - warm ("yellow") light (sodium); 4 000K ... 5 400K - cold ("blue") light (mercury). |
2 700K - warm light; 2 900K ... 4 000K - white light; 5 400K ... 6 400K - cold light. |
| Color rendering index, Ra | 100 | 90… 100 | 60… 90 | 80… 90 | 20… 60 | 80… 100 |
| Light output, lm / W | 15… 20 | 30 | 30… 60 | 80… 100 | 100 | 40… 100 |
| Economical | low | low | mean | high | high | high |
| Durability | 1 000 | 3 000 | 10 000 (CFL) 20 000 (LL) |
15 000 | 30 000 | 100 000 |
| Networking | direct | immediate; through a step-down transformer | through the starting-regulating device (Gear) | through the starting-regulating device (Gear) | through the source constant voltage (tape) or current (discrete diodes 1 ... 10W) | |
| Colored lamps | there is | there is | there is | no | no | there is |
| Ability to adjust brightness | possible, by any standard dimmer | possible, special dimmer | is impossible | is impossible | possible, special dimmer | |
| Changes in wiring for dimmer | no | no | yes | not applicable | not applicable | yes |
| Rated brightness | immediately after switching on | immediately after switching on | 0,5 ... 1 min after switching on | 2 ... 3 minutes after switching on | 2 ... 3 minutes after switching on | immediately after switching on |
| Switch-on frequency | high; The luminaire can be turned on immediately after turning it off | high; The luminaire can be turned on immediately after turning it off | low, after switching off the lamp can not be turned on 5 ... 10 min | high; The luminaire can be turned on immediately after turning it off | ||
| Wet rooms | forbidden* | allowed * | forbidden* | forbidden* | forbidden* | allowed * |
| Basic lighting | oK | oK | oK | oK | oK | medium |
| Directional illumination | medium (for reflex) | oK | badly | oK | not applicable | medium |
| Broken illumination | good (for reflex) | oK | badly | oK | not applicable | oK |
| Broken illumination (in niches) | badly | badly | oK | not applicable | not applicable | oK |
| Street Lighting | medium | oK | badly | oK | oK | oK |
| Short description | Classic, familiar, yellowish light. Well suited for most interiors. Strong heating, which greatly limits the use. Gradually replaced by CFL. | Light more white than LN, provides better color rendition in the kitchen, in the bathroom. In addition, the bathroom is used for security reasons. Look good in high-tech interior. Local lighting (interior details, furniture, paintings) | A wide range of colors allows you to replace both LN and GLN. Good LN replacement due to low heating and identical dimensions. Because of the built-in electronics, do not use it under high humidity. The light flux is very scattered. | The main application is exposition, street lighting, large rooms, workshops, shops, garages. Excellent color rendition. They need a bulky ballast. | Strongly yellow (sodium) or cool white (mercury) color. Street, industrial lighting. They need a bulky ballast. | A wide range of colors, color designs, extremely small dimensions make LED lamps ideal for decorative lighting. Compact power supplies. For basic lighting while too expensive, but technology has a great resource development. |
PRINCIPLES OF ACTION OF DIFFERENT TYPES OF LAMP.
Incandescent lamps.
A tungsten spiral placed in a flask from which air is pumped is heated by the action of electric current. Typical for LN light output - 10-15 Lm / W. LN is more of a heater than a lighting device: the main part of the electricity filament that feeds the filament does not turn into light, but into heat. Only 10-15% of light energy is converted into light. LN service life, as a rule, does not exceed 1 000 h. Light output and service life are determined by the temperature of the spiral. When the temperature of the helix increases, the brightness increases, but at the same time the service life is shortened. The reduction in service life is a consequence of the fact that the evaporation of the material from which the thread is made is faster at high temperatures, whereupon the bulb darkens, and the filament becomes thinner and thinner, after which the lamp breaks down.
The main types of incandescent lamps are general purpose lamps, special-purpose lamps, decorative lamps and reflector lamps. Reflector mirror lamps provide a beam of light, ideal for lighting a specific area. Built-in reflector provides maximum axial force of light.
Halogen bulbs.
Modern version of incandescent lamps. Technological innovations - the addition of halogenides to the bulb of the lamp, the use of special varieties of quartz glass, the "return" of thermal radiation to the spiral of lamps, with the help of special reflectors, isolated GLN into a special type of light source. As well as conventional lamps incandescent lamps are high-temperature radiators. To withstand high temperatures and pressure, the halogen lamp bulb is made of quartz glass. Quartz glass transmits ultraviolet rays, so leading manufacturers of lamps add to the quartz additives that delay UV radiation.
Light output of modern GLN is about 30 Lm / W. A typical value of the color temperature is 3000 K. There are also GLN " daylight"- 4000-4200 K. GLN have an excellent color rendition. "Spot" shape of the lamp allows you to control the width of the "beam" in a wide range with the help of miniature reflectors. In the interior design GLN has now become the standard. Halogen lamps allow creating scattered, soft, shadowless lighting, or clearly directed, spotlight.
The brightness level of halogen lamps can be adjusted. Halogen lamps for 220V operate directly from the network without transformers, models low voltage connect to the network via a transformer.
The advantage is also the fact that the amount and quality of light given by the lamp is constant throughout the life of the lamp.
For use in the interior are particularly popular low-voltage LMW MR-11 and MR-16 (power from 10 to 75 W), equipped with a reflector, which allows to focus the beam in an angle of 8-36 degrees.
Types of halogen lamps.
Linear dvuhzokolnye halogen lamps.
Mostly produced mains voltage (230 V) with the R7s socket. They differ in power: from 60 to 2000 W and along the length of the bulb from 78 mm to 334 mm. Most often used in searchlights. Most models are designed to work only in a horizontal position, the deviation is not more than 10 degrees. Violation of this condition leads to turbidity of the bulb and the failure of the lamp before the time.
Lamps halogen point without reflector (capsule).
Capsule halogen lamps - the most compact of halogen lamps, are manufactured using low pressure technology and can be operated in open luminaires without a protective glass. There are low-voltage (mostly 6, 12, 24 V) and mains voltage. Usually, as a cap in capsule lamps, a flask with rigidly fixed terminals of tungsten wire is used. However, despite the physical absence of the cap, in catalogs and technical documentation such pinout is called a "cap of type G ..., GY ...", the numbers after the letters indicate the distance in millimeters between the terminals of the contacts. The letter "G" stands for the pin socket, the following letters for the edge feature of the lamp at the contacts and the location of the contacts.
Halogen lamps with a reflector.
The device of halogen lamps with a reflector differs in that the mirror reflector together with the cap is glued to the bulb of the lamp. Mirror coating is carried out by spraying on a glass reflector of chemically pure aluminum (opaque coating) or a special translucent coating. Lamps with a translucent (interference dichroic) coating almost do not heat the illuminated surface. There are modifications with protective glass and without glass.
The dimensions of the reflectors are of several types:
1. MR 11, diameter 35 mm
2. MR 13, diameter 42 mm
3. MR 16, diameter 51 mm
4. MR 18, diameter 58 mm
5. Reflector with a diameter of 70 mm
6. A reflector with a diameter of 111 mm.
Halogen lamps with PAR reflector.
The bulb of PAR lamps (Parabolic Aluminum Reflector) is made of pressed glass, which has an increased mechanical strength and is resistant to a sharp temperature drop (the lamps do not break down when they get a splash of cold water). Inside the bulb there is a quartz halogen burner, the light flux of which is concentrated by a mirror reflector. The corrugated front glass contributes to the uniformity of the structure of the light spot and protects the burner from dust and touch. Lamps are produced in two versions - Spot - with a narrow light beam and a flood - with a wide beam of light. Socle E27 and E14. Powered by mains voltage. There are models with built-in transformer. The service life of PAR lamps is 2.5 times greater than that of conventional incandescent incandescent lamps. Such lamps are advisable to use for accenting indoor and outdoor lighting. Lamps are produced in sizes similar to the size of mirror incandescent lamps, therefore PAR lamps can be recommended for use in recessed lighting fixtures for incandescent lamps.
Fluorescent lamps.
Low-discharge discharge lamps are a cylindrical tube with electrodes into which mercury vapor is pumped. Under the action of an electric discharge, mercury vapor emits ultraviolet rays, which, in turn, cause the phosphor placed on the tube walls to radiate visible light. LL provide a soft uniform light, but the distribution of light in space is difficult to control due to the large radiation surface. Due to the fact that the LL creates diffuse light and thanks to the high light output, they are ideal for lighting large rooms where it is not necessary to turn the lighting on and off frequently during the day. For work fluorescent lamps special control gear is needed.
One of the main advantages of LL is durability (service life up to 20,000 hours). Due to economy and durability, LL has become the most common light source in public premises. In countries with mild climate, LL is widely used in outdoor lighting of cities.
Compact fluorescent lamps.
They produce light according to the same principle as conventional fluorescent lamps. The phosphor applied on internal walls is transformed ultraviolet radiation in visible light. By choosing a certain kind of phosphor, you can change the color of the lamp's light. Bending the flask of a conventional fluorescent lamp and dividing it into several smaller ones, the developers succeeded in creating a CFL, which in its dimensions is identical to a standard incandescent lamp.
All CFLs provide high profitability. Electricity costs are reduced to 80% compared to incandescent lamps of the same brightness, and the lifespan of the CFL is 10-12 times higher than that of incandescent lamps.
KLL, like a linear fluorescent lamp, requires the use of ballasts. KLL are divided into 2 groups: with integrated (integrated) gear and external gear. KLL with E14 and E27 bases have built-in ballasts, so they can easily be used in place of standard incandescent lamps. CFL with external ballasts require additional equipment.
There are about 20 types of socles for such CFLs.
High-pressure discharge lamps.
The principle of high-pressure discharge lamps is the glow of the filler in the discharge tube under the action of electric arc discharges. The two main discharges of high pressure are mercury and sodium. Both give fairly narrow-band radiation: mercury - in the blue region of the spectrum, sodium - in the yellow, so the color rendition of these lamps is not very good: for mercury - 40-60, for sodium - 20-30.
Mercury and sodium light sources are widely used for outdoor lighting. The use of sodium lamps is more economical than mercury lamps.
The addition of various metals to the discharge tube of halogenides of various metals made it possible to create metal halide lamps characterized by a very wide spectrum of radiation and excellent parameters: high light output (up to 100 lm / W), good and excellent color rendition (Ra = 80-98), color temperature range from 3000K to 6000 K, the average service life of about 15,000 h. IPF is widely used in architectural, landscape, technical and sports lighting.
PUSH-REGULATORY APPARATUS
For the ignition of fluorescent lamps and high-pressure discharge lamps, special equipment is needed to ensure ignition of the discharge and stabilization of the current. To ignite the lamp, you need an overvoltage that is more than twice the working voltage between the lamp electrodes. After the ignition of the lamp, at the moment when the ionization process in it increases sharply, the current-limiting resistance must automatically turn into the lamp circuit.
The ballasts are a lighting product, through which the lamp is powered by electrical network, necessary modes of ignition, ignition and operation of the gas discharge lamp are provided. Structurally, the gear is designed as a single unit, or in several separate units.
The increase in light output, mainly based on a more efficient conversion of electrical energy in the ultraviolet region of the spectrum of mercury atoms at 185 nm and 254 nm.
The use of modern electronic ballasts allows (above all, for fluorescent lamps) to significantly improve light comfort, economy and operational safety. There are electronic ballasts with the possibility of dimming. They provide smooth, blinking light control of fluorescent lamps in the range from 3% to 100% for compact fluorescent lamps and from 1% to 100% for linear fluorescent lamps.
The luminous efficiency in this case is 625 lm / vpg.
Luminous efficiency of 100 - 170 lm / W, service life 5 - 7 thousand hours, used gl. The light output is 100 - 140 lm / W, the service life is up to 15 - 20 thousand h, it is used for outdoor use.
Light output is directly dependent on the temperature of the lamp body. In Fig. 3 - 7 shows such a dependence for gas-filled incandescent lamps.
Optimal ratio of the thickness of the layer and the size of the phosphor grain. The luminous efficiency (or luminosity of the luminescence) of the screen depends strongly on the size of the phosphor grains. As a rule, coarse-grained screens have a greater light output. However, the use of coarse-grained phosphor layers is in some cases impractical. The grain size limits the resolution of the screen, since the luminous spot on the screen can not fundamentally be smaller than the amount of the phosphor luminescent under the electron beam. The most noticeable decrease in the light output is observed when the sulfide phosphors are crushed. Therefore, sulphides are usually used with relatively large grains - up to 5 - 8 microns.
The light output (the ratio of the lamp's light flux to its electric power) for normal lamps lies in the range 8 7 - 19 7 lm / W - for lamps at 127 V and 7 0 - 18 7 lm / W for lamps at 220 V. The smaller limiting value of light output refers to lamps with a power of 15 watts, and more - to lamps with a power of 1500 watts.
The luminous efficiency in some scintillators is proportional to the energy of the exciting particle or quantum.
Light output is the main economic indicator of light sources. However, this indicator should be considered together with the service life and cost.
The light output of these lamps reaches 100 lm / W, the color temperature is 6000 K, the color rendering index is 80 - 90, and the service life is several thousand hours. In terms of the use of these lamps in projectors, the relatively small dimensions of the discharge arc and the noncriticality to the burning position are also important. When the projectors are connected to different phases of the network and the spatial displacement of their light beams, the pulsations of the illumination on the field can be minimized. At the same time, in the development of powerful metal halide lamps, an important problem was solved, such as their instantaneous re-ignition after a short-term loss of voltage in the supply network.
Luminous efficiency at direct current is equal to approx.
The light output shows the economy of the light source and is characterized by the ratio of the light flux of the light source to the electric power consumed by it.
The light output - the ratio of the light - lamp flux to its electric power - for normal lamps lies in the range of 8 7 - 19 7 lm / W for lamps at 127 V and 7 0 - 18 7 lm / W for lamps at 220 V.
The light output characterizes the economy of the lamp, since the larger the luminous flux emitted by the lamp by 1 W, the more profitable it is.
Spectral characteristics of the cesium lamp.
The light output characterizes the economy of the lamp: the more light the lamp radiates per unit of input power, the more economical it is.
Dependence of power I, light flux Ф, voltage on lamp U, current / on mains voltage. The characteristics of the times of the horn of xenon lamps of high intensity. Light output increases with increasing specific power, tending to the limit of about 45 - 48 lm / W.
Functional scheme for supplying an impulse lamp with an energy storage device (IL is a flash lamp included in a discharge circuit K with an electric energy storage unit Y. It is a secondary energy source for a lamp. charger. PI is the primary source of energy. GI - generator of ignition pulses and HSS - control unit, synchronization and protection. A typical dependence of the force of St. the luminous intensity of the light.The maximum difference in the shape of the indicatrix of illumination studied in the nominal modes of IL The luminous efficiency of tubular xenon ILs reaches 60 lm / W. It is related to the spatial distribution of the radiation by the quantity is the equivalent solid angle QD, equal to the ratio of the light energy Q to the illumination of в in the direction taken for the main radiation direction.
Spectral distributions of efficiency in a single solid angle in the direction perpendicular to the tube axis for tubular xenon lamps. The spectral distribution of the efficiency in a single solid angle for the ISsh7 glass lamp (xenon, 0 22 MPa, (- mm 1000 V, 6800 pF, 10 35 MKS, / 2 kHz, / cp - 4 8 cd.) The light output of spherical ILs usually does not exceed 15 lm / W. The increase in the distance between the electrodes is accompanied by an approximately linear increase in the light output.
The light output characterizes the light flux obtained at a cost of 1 W of electric power.
Light output is usually expressed in lumens per watt of radiant flux. It should not be confused with the term return in application to a practical light source, since the latter is based on the power supplied to the source, rather than on the energy flux radiated by the source.
The light output increases linearly depending on the current density of the beam at low current densities, then it begins to grow slower and approaches saturation at densities of about 1 μA / cm and above. The conversion efficiency increases with increasing voltage and decreases with increasing current density.
The luminous efficiency depends on the product of the spectral emission characteristic and the sensitivity of the eye. Since the eye has the greatest sensitivity in the yellow-green region of the spectrum (wavelength about 5560 angstroms), the yellow-green phosphors are most effective. Zinc-cadmium sulfide, activated by silver or copper, and zinc-beryllium silicate activated by manganese, give the maximum energy near the area of maximum sensitivity of the eye.
The light output characterizes the energy efficiency of the phosphor and is expressed in terms of the ratio of the strength of light to the energy of the exciting electron beam.
Scheme of an electron-optical converter with parallel transfer. Usually light output is expressed in candles divided by watts.
The light output of titanium during its combustion in oxygen is obtained somewhat less than that of magnesium and aluminum tested under the same conditions. The amount of heat released during the combustion of titanium is also less than for magnesium or aluminum.
The light output of the phosphor does not disappear instantly after the cessation of the action of electrons on it, but decreases gradually according to an exponential law. This phenomenon is known as phosphorescence. Depending on the composition of the phosphor, the duration of the afterglow can vary from a few microseconds to several seconds. The screens of electron-beam tubes are characterized by the spectral composition of the luminescence and the duration of afterglow. To ensure that the screen of the cathode ray tube does not accumulate a negative charge creating a retarding field for electrons moving to the screen, it is necessary that the screen emits one or more secondary electrons for each primary electron striking it. For any material, the ratio of the number of secondary electrons to the primary electrons is a function of the energy of the primary electrons.
Energy balance of lamps. a is a fluorescent lamp. b - incandescent lamp. c - fluorescent lamp without. Light output of gas-discharge lamps is quite high, but they give color light, which is a significant disadvantage of lamps of this type. The yellow light of sodium lamps and the blue-green light of mercury lamps make people's faces pale; the color reproduction of painted surfaces illuminated by the light of such lamps is highly distorted.
The light output of a light source is defined as the ratio of the light flux emitted to it to the consumed electric power. The greater the luminous flux emitted by a lamp per unit of power, the greater its economy.
The light output of a 100-watt bulb is 18 8 lm / W. The lamp sends to the surrounding space hourly 12 kJ of light energy.
The total luminous efficiency of the latter is only about 10% of the exterminated current, while about 70% falls on infrared radiation and about 20 passes directly into heat. In a mercury lamp the situation is different: for visible light (blue-green hues), about 25% of the current consumed here goes, and most of the remainder is expended on the excitation of ultraviolet rays.
Light output of modern incandescent lamps varies from 7 to 19 lm / W. Significant progress in the development of incandescent lamps is the use of an iodine cycle in them. In the lamps special design introduced a certain amount of iodine, whose atoms under the influence of high temperature form compounds with tungsten particles - tungsten iodide. This compound in the high-temperature zone (near the filament) again decomposes into iodine and tungsten.
Color Specifications fluorescent lamps in accordance with GOST 6825 - 70. The light output of mercury-quartz lamps DRL is also significantly higher than that of incandescent lamps, and does not include losses in gears from 40 to 50 lm / w, depending on their power.
The luminous efficacy of modern projector lamps ranges from 12 to 17 1m / W, reaching up to 30 lm / W when the filament is sintered by reducing the life of the lamp.
The light output of the radiation should not be mixed with the light output of the source equal to the number of lumens of the light flux obtained for each watt of power expended for obtaining radiation.
However, the light output of silicates and tungstates is not sufficient to ensure a high brightness of the screen luminescence at large beam-traveling speeds across the screen. In recent years, high-performance sulphides have been developed, which are crushed without significant decrease in light output. Such sulfides with green and blue luminescence gradually replace silicates and tungstates. But even now, due to the high physico-chemical stability, silicates are widely used in the production of oscillographic tubes.
If the light output of normal incandescent lamps is between 7 and 20 lm / W, for fluorescent lamps it is 75 - 80 lm / W, and the service life of the latter is 5000 h, exceeding by 5 times the service life of incandescent lamps. However, fluorescent lamps also have disadvantages: the need for relatively complex triggering devices, pulsation of the light flux and the associated stroboscopic effect when working on alternating current, small suitability for local lighting.
Such a low light output of a thermal radiator is explained by the fact that when chaotic motion of atoms and molecules, not only light (visible), but also other electromagnetic waves are excited, which do not exert light on the eye. Therefore, it is impossible to selectively force the body to emit only those waves to which the eye is sensitive: invisible waves are necessarily emitted.
Significantly more light output of electric arcs, the positive crater of which has a temperature of about 4000 K. In conventional arcs, the main part of the radiation (from 85 to 95%) is radiated by a positive crater, about 10% by a cathode and only 5% by the glow of a gas cloud between the electrodes. In the arcs of intense combustion, in which the refractory salts of some elements with high emissivity (rare earths) are introduced, the role of the cloud increases and the crater accounts for only 40-50% of the total radiation. Although, apparently, in such arcs the radiation is almost exclusively thermal, nevertheless, due to the high selectivity of the radiation of the elements introduced into the composition of the cloud, the light output of such sources proves to be higher than for hot coal and metals.
Fluorescent Lamp. If the light output of normal incandescent lamps ranged from 7 to 20 lm / W, for fluorescent lamps it is 75 to 80 lm / W, and the service life of the latter is 5000 h, exceeding the service life of incandescent lamps 5 times.
Significantly more light output of electric arcs, the positive crater of which has a temperature of about 4000 K. In the arc of intense combustion (current up to 300 A), the crater temperature reaches 5000 K, and in arcs under a pressure of about 20 atm, Lummer managed to bring the crater temperature to 5900 K, those. get a source close in its light properties to the Sun. In ordinary arcs, the main part of the radiation (from 85 to 95%) is radiated by a positive crater, about 10% by a cathode and only 5% by the glow of a cloud of gases between the electrodes. In the arcs of intense combustion, in which the refractory salts of some elements with high initial capacity (rare earths) are introduced, the role of the cloud increases and the crater accounts for only 40-50% of the total radiation. Although, apparently, in such arcs the radiation is almost exclusively thermal, nevertheless, due to the high selectivity of the radiation of the elements introduced into the composition of the cloud, the light output of such sources proves to be higher than for hot coal and metals.
If the light output of normal incandescent lamps is between 7 and 20 lm / W, for fluorescent lamps it is 75 - 80 lm / W, and the service life of the latter is 5000 h, exceeding by 5 times the service life of incandescent lamps.
Decrease in the light output is compensated by increasing the power of the driving beam to 45 W; for a filament of a passing light, a power of 35 W is sufficient, since the loss of the light flux is reduced because of the absence of a metal screen. Due to some shift of the filament of the passing light away from the optical axis of the reflector, the light beam is slightly deflected to the side. As a result, the side of the road corresponding to the direction of the car's movement is illuminated more strongly than the side on which the counter motion occurs, which leads to a weakening of the blinding action. However, part of the rays in the passing beam, going horizontally and upward, still leads to the fact that the total blinding effect is somewhat greater than with Bilux lamps. Because of this, a small inclination of the optical axis of the headlamp is required, which is associated with a slight decrease in the range of illumination.
The magnitude of the light output is directly proportional to the temperature of the filament.
The values of the light output for direct-vision tubes operating at voltages of 14-18 kV and current densities of 0-1-1 mka / cm2 reach 2 to 3 w / w for non-aluminium and 3-bw / w for aluminum-russia shields.
The increase in light output of light bulbs by only 10% is equivalent to an additional release of more than 60 million pampas a year.
Improving the light output of mercury lamps is achieved through the addition of iodides atrium, thallium and indium, which, when mixed with mercury vapor, give additional light radiation. In this case, the light output rises by a factor of 1-5 - 2, and the chromaticity of the radiation is significantly improved. Such lamps are called metalloid-loid.
In this case, the light emission of radiation is 620 tons / lm / W.