High pressure mercury lamps. Switching scheme, marking and designation of mercury lamps

Ultra-high pressure arc lamps (SHPL) include lamps operating at pressures of 10 × 10 5 Pa and above. At high pressures of gas or metal vapor, with a strong approach of the electrodes, the near-cathode and near-anode regions of the discharge are reduced. The discharge is concentrated in a narrow spindle-shaped region between the electrodes, and its brightness, especially near the cathode, reaches very high values.

Such an arc discharge is an indispensable light source for projector and floodlight devices, as well as a number of special applications.

The use of mercury vapor or an inert gas in lamps gives them a number of features. The production of mercury vapor at the appropriate pressure, as can be seen from the consideration of high pressure, in the article "", is achieved by dosing mercury in the lamp bulb. The discharge is ignited as low pressure mercury at ambient temperature. Then, as the lamp ignites and heats up, the pressure increases. The operating pressure is determined by the steady temperature of the bulb, at which the electric power supplied to the lamp becomes equal to the power dissipated in the surrounding space by radiation and heat transfer. Thus, the first feature of ultra-high pressure mercury lamps is that they ignite quite easily, but have a relatively long warm-up period. When they go out, re-ignition can be carried out, as a rule, only after complete cooling. When the lamps are filled with inert gases, the discharge after ignition almost instantly enters a steady state. Ignition of a discharge in a gas at high pressure presents certain difficulties and requires the use of special igniting devices. However, after the lamp has gone out, it can be re-ignited almost instantly.

The second feature that distinguishes an ultrahigh-pressure mercury discharge with a short arc from the corresponding gas discharges is its electric mode. Due to the large difference between the potential gradients in mercury and inert gases at the same pressure, the burning voltage of such lamps is significantly higher than with gas filling, due to which, at equal powers, the current of the latter is much greater.

The third significant difference is the emission spectrum, which, for gas-filled lamps, corresponds in spectral composition to daylight.

The noted features have led to the fact that arc lamps are often used for filming and film projection, in simulators of solar radiation and in other cases when correct color reproduction is required.

Lamp device

The spherical shape of the lamp bulb was chosen from the condition of ensuring high mechanical strength at high pressures and small distances between the electrodes (Figures 1 and 2). A spherical flask made of quartz glass has two diametrically located long cylindrical legs, in which the inputs connected to the electrodes are sealed. The long leg length is necessary to remove the lead from the hot bulb and protect it from oxidation. Some types of mercury lamps have an additional ignition electrode in the form of a tungsten wire soldered into the bulb.

Figure 1. General view of ultra-high pressure mercury-quartz lamps with a short arc of various power, W:
a - 50; b - 100; in - 250; G - 500; d - 1000

Figure 2. General view of xenon ball lamps:
a- DC lamp with power 100 - 200 kW; b- 1 kW alternating current lamp; in- 2 kW alternating current lamp; G- 1 kW DC lamp

The designs of the electrodes are different depending on the kind of current that feeds the lamp. When operating on alternating current, for which mercury lamps are designed, both electrodes have the same design (Figure 3). They differ from the electrodes of tubular lamps of the same power in greater massiveness, due to the need to reduce their temperature.

Figure 3. Electrodes for AC mercury lamps with a short arc:
a- for lamps up to 1 kW; b- for lamps up to 10 kW; in- solid electrode for powerful lamps; 1 - core made of torn tungsten; 2 - a covering spiral made of tungsten wire; 3 - oxide paste; 4 - gas absorber; 5 - base made of sintered tungsten powder with the addition of thorium oxide; 6 - forged tungsten part

When operating lamps on direct current, the burning position of the lamp becomes important, which should be only vertical - anode up for gas lamps and preferably anode down for mercury lamps. The location of the anode at the bottom reduces the stability of the arc, which is important due to the counterflow of electrons directed downwards and hot gases rising upwards. The upper position of the anode makes it necessary to increase its size, since in addition to heating it due to the greater power dissipated at the anode, it is additionally heated by a stream of hot gases. For mercury lamps, the anode is placed at the bottom in order to ensure more uniform heating and, accordingly, reduce the warm-up time.

Due to the small distance between the electrodes, mercury ball lamps can operate on alternating current from a 127 or 220 V mains. kW - (20 - 10) × 10 5 Pa.

Ultra-high pressure lamps with a spherical bulb are most often filled with xenon because of the convenience of its dosage. The distance between the electrodes is 3 - 6 mm for most lamps. Xenon pressure in a cold lamp (1 - 5) × 10 5 Pa for lamps with power from 50 W to 10 kW. Such pressures make ultra-high pressure lamps explosive even when not in use and require the use of special casings for their storage. Due to strong convection, lamps can only work in a vertical position, regardless of the type of current.

lamp radiation

The high brightness of mercury ball lamps with a short arc is obtained due to the increase in current and the stabilization of the discharge at the electrodes, which prevent the expansion of the discharge channel. Depending on the temperature of the working part of the electrodes and their design, different brightness distributions can be obtained. When the temperature of the electrodes is insufficient to ensure the arc current due to thermionic emission, the arc contracts at the electrodes into small bright luminous dots and acquires a spindle shape. The brightness near the electrodes reaches 1000 Mcd/m² or more. The small size of these regions leads to the fact that their role in the total radiation flux of the lamps is insignificant.

When the discharge is contracted at the electrodes, the brightness increases with increasing pressure and current (power) and with decreasing distance between the electrodes.

If the temperature of the working part of the electrodes ensures that the arc current is obtained due to thermionic emission, then the discharge, as it were, spreads over the surface of the electrodes. In this case, the brightness is more uniformly distributed along the discharge and still increases with increasing current and pressure. The radius of the discharge channel depends on the shape and design of the working part of the electrodes and almost does not depend on the distance between them.

The luminous efficiency of lamps increases with the growth of their specific power. With a spindle-shaped discharge, the light output has a maximum at a certain distance between the electrodes.

The radiation of mercury ball lamps of the DRSh type has a line spectrum with a strongly pronounced continuous background. The lines are greatly expanded. There are no radiations with wavelengths shorter than 280 - 290 nm at all, and due to the background, the proportion of red radiation is 4 - 7%.

Figure 4. Brightness distribution along ( 1 ) and across ( 2 ) discharge axis of xenon lamps

The discharge cord of DC globular xenon lamps, when operated in a vertical position with the anode up, has the shape of a cone, resting with its tip on the tip of the cathode and expanding upward. A small cathode spot of very high brightness is formed near the cathode. The brightness distribution in the discharge cord remains the same when the discharge current density changes over a very wide range, which makes it possible to construct uniform brightness distribution curves along and across the discharge (Figure 4). The brightness is directly proportional to the power per unit length of the arc discharge. The ratio of the luminous flux and luminous intensity in a given direction to the length of the arc is proportional to the ratio of power to the same length.

The emission spectrum of ultrahigh pressure globular xenon lamps differs little from the emission spectrum.

Powerful xenon lamps have an increasing current-voltage characteristic. The slope of the characteristic increases with increasing distance between the electrodes and pressure. The anode-cathode potential drop for xenon lamps with a short arc is 9 - 10 V, and the cathode accounts for 7 - 8 V.

Modern ultra-high pressure ball lamps are produced in various designs, including those with collapsible electrodes and water cooling. The design of a special metal collapsible lamp-luminaire of the DKsRM55000 type and a number of other sources used in special installations has been developed.

Mercury lamps of various designs are still used today, as they have occupied their niche: they are used in the organization of a lighting system for large industrial facilities, streets. The general designation for the most common high-pressure version is DRL, which means an arc mercury fluorescent light bulb. This variety represents gas-discharge light sources and is characterized by hazard class 1 due to the fact that, among other things, mercury is included in the composition.

Device Features

The design provides for several main elements:

• the base is the contact part, and the lighting elements with the holder E40, E27 are easy to install in any modern lamp;
• quartz flask - contains an inert gas and a certain amount of mercury, connected to the electrodes;
• outer flask - made of heat-resistant glass, shaped like an analogue of incandescence, inside there is a quartz flask (burner).

Gas-discharge light sources are covered with a phosphor from the inside. The arc lamp contains carbon dioxide, which fills the outer bulb. Most of these lighting elements operate by means of a ballast (ballast), but there is also a separate type - gas discharge lamps of direct switching, which do not require the installation of ballasts, but are connected directly to the network.

DRL lamp design

Arc light sources operate on the basis of the phenomenon of luminescence. In this case, the glow occurs under the influence of ultraviolet radiation. It is also produced by mercury vapor, which is part of the gaseous filling of the quartz flask. These processes occur under the condition that an electric discharge passes through a quartz burner.

Overview of Existing Views

High-pressure gas-discharge light sources, which include DRL arc lamps, are divided into two main groups: general and highly specialized. The first option is installed in a street lighting fixture. The second group of high pressure light sources is used in medicine, certain industries, and agriculture.

In addition, gas discharge lamps are divided into types in accordance with structural and functional differences. Power range: from 80 to 1000 W. More powerful versions of 100 W, 250 W, 400 W, etc. are more often used. Moreover, there is a division according to the number of electrodes: two-electrode (power from 80 to 1,000 W); four-electrode (250 -1000 W).

Arc metal halide light sources (DRI)

The peculiarity of such lamps lies in radiating additives, hence the designation: DRI (arc mercury lighting elements with radiating additives). By external signs, this light source is similar to the analogue of the DRL.

DRI mercury lamps

The difference between them lies in the fact that the composition of DRI also includes specialized components that are strictly dosed: sodium halide, indium and some others. This contributes to a significant increase in radiation efficiency.

The flask may be in the form of an ellipsoid or a cylinder. Mercury lamps of this type today increasingly contain a ceramic burner instead of a quartz counterpart. Also, gas-discharge light sources of this group have a more advanced design, in particular, the shape of the inner bulb can be spherical. DRI mercury lamps require the inclusion of a choke in the circuit.

Gas-discharge lighting elements of this type are used in the organization of outdoor lighting: parks, streets, squares, they are used as lighting for buildings, shopping and exhibition halls, as well as large venues (sports, football fields).

Metal halide with a mirror layer (DRIZ)

Mercury lamps of this type have a similar composition with DRI analogues: the main filling + radiating additives. But in addition to that, the design provides a mirror layer. Thanks to this feature, DRIZ high-pressure bulbs provide a directed beam of light.

Metal halide light sources with a mirror layer (DRIZ)

They are used in conditions of poor visibility, since a high level of power, along with design features, contributes to the organization of effective illumination of an area of ​​\u200b\u200bthe object due to directional glow.

Mercury-quartz spherical light sources (DRSH)

Such high pressure bulbs stand out from a number of analogues. The following factors contribute to this: the spherical shape of the bulb, the radiation of increased intensity. And in addition to that, a mercury-quartz lamp is characterized by ultra-high pressure.

High pressure bulbs DRSH

Scope - highly specialized areas, in particular, projection systems, laboratory equipment.

Mercury-quartz (PRK, DRT)

This type of light bulb has a different bulb shape than the above-considered counterparts. For example, PRK stands for direct mercury-quartz lighting element. This is the original designation of a DRT lamp (arc mercury tubular).

The transition to another marking occurred in the 80s. last century. A mercury-quartz lamp in this design is characterized by the shape of a bulb in the form of a cylinder, while the electrodes are located on the end sections of the bulb.

Emission color

Due to the presence of a phosphor in the design, mercury-containing lamps at the output give a color as close as possible to white. A neutral hue is obtained by mixing the radiation of the gaseous components of the bulb and the phosphor. In particular, mercury vapor produces a glow of different colors: blue, green, purple, orange. And besides this, they emit ultraviolet (soft, hard).

The combined glow of the phosphor and the gaseous filling of the flask located inside the DRI high-pressure bulb allows you to get different colors of the glow: green, purple, etc. This is achieved by changing the composition and ratio of radiating additives.

Ballasts

Fluorescent mercury lamps are connected to the network in most cases through a choke (ballast). In fact, this node is a current limiter that contributes to the smooth commissioning of a high-pressure light source. In the absence of a ballast, the DRL bulb will burn out due to the passage of high currents through the electrodes.

However, there are analogues of direct inclusion. For their normal operation, a choke is not required; you can install a high-pressure lamp in the luminaire. Such light sources are designated DRV (arc mercury tungsten). They are similar in characteristics to the DRL variant. The choice of ballast is made on the basis of data on the power of the light bulb.

General specifications

The determination of the most suitable type of lamp is carried out taking into account the main parameters of the light source:

• supply voltage - usually indicated for direct-on lighting elements installed without a choke (DRV);
• power - varies from 80 to 1,000 W;
• the luminous flux directly depends on the level of the generated load: it varies from 1,900 to 59,000 lm;
• burning time: from 1,500 to 20,000 hours, while the shortest period of operation is noted for direct-on tungsten bulbs;
• base type: E27, E40;
• dimensions of the product - vary depending on the version of the lamp.

Features and characteristics of various light sources

For DRL light sources and other analogues connected with a choke, the lamp voltage can be indicated.

Storage and disposal

Considering that mercury (hazard class 1) is included in the lighting elements of the DRL type and other similar designs, it is prohibited to store products with damaged bulbs in rooms unprepared for this. Especially when it comes to the amount of hazardous waste on an industrial scale. Storage, transportation and further disposal should be carried out by organizations that have the appropriate license (UNEP).

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The emission spectrum of a mercury lamp has a maximum at a wavelength of 365 nm.

The emission spectrum of mercury lamps has a line structure, and when photosensitive layers containing a diazo compound are exposed, light with wavelengths of 3650, 4050 and 4358 A actively acts. In the intervals between these lines, the lamp radiation (continuous radiation background) is insignificant and only for sources of high and ultrahigh pressure, the background value reaches 0 1 - 0 25 of the radiation intensity of the main lines. From what has been said, it follows that even with a slight shift in the absorption region of a diazotype material relative to the position of the main lines of the mercury spectrum, a decrease in the sensitivity of the material is possible. Turner 77] observed, in particular, significant discrepancies between the experimentally found and calculated values ​​of the yield energy when a diazo compound was irradiated with monochromatic light with a wavelength of 3650 A and found that the relative sensitivity at 3130 A is only 25% of that at 3650 A.

The emission spectrum of medium-pressure mercury lamps has many high-intensity lines, but the intensity of the 2537 nm line decreases sharply.

In the emission spectra of mercury lamps, along with lines, with increasing pressure, the continuous spectrum, the so-called background, becomes more and more intense. At very high pressures (several tens of atmospheres), the spectra become continuous with separate maxima in those places where the lines were located at low pressures.

The results of these experiments and other observations make it possible, with some approximation to the truth, to conclude that hexachlorane quenches that part of the radiation spectrum of a mercury lamp which promotes the formation of the y-isomer.

The emission spectrum of mercury lamps has a line structure, and when exposed to photosensitive layers containing diazo compounds, light with wavelengths of 3650, 4050 and 4358 A actively acts. In the intervals between these lines, the lamp radiation (continuous radiation background) is insignificant and only for sources of high and ultrahigh pressure the background value reaches 0 1 - 0 25 of the radiation intensity of the main lines. From what has been said, it follows that even with a slight shift in the absorption region of a diazotype material relative to the position of the main lines of the mercury spectrum, a decrease in the sensitivity of the material is possible. Turner observed, in particular, significant discrepancies between the experimentally found and calculated values ​​of the yield energy when a diazo compound was irradiated with monochromatic light with a wavelength of 3650 A and found that the relative sensitivity at 3130 A is only 25% of the sensitivity at 3650 A.

Often in instruments, the wavelength drum associated with the prism or grating rotation mechanism is calibrated in relative units. As a standard spectrum in the visible and ultraviolet region, the radiation spectrum of a mercury lamp is used, which consists of a small number of intense lines. Such a calibration against a standard substance should be repeated periodically, since in the course of work the established correspondence is violated.

To this end, instead of sunlight, the sample is illuminated with lamps whose intensity can be compared with direct sunlight. Typically, the luminaires are carbon arc or high pressure xenon lamps; sometimes mercury lamps are used. The radiation spectrum of mercury lamps is dominated by ultraviolet rays, which are the most active component of daylight in the process of fading; therefore, the use of these lamps contributes to the additional acceleration of testing. Extrapolation of correlation results for unknown materials can lead to errors.

Before starting measurements, the installation is calibrated in terms of wavelengths. To do this, the input part of the spectrograph - YSP-51 is illuminated by a light source with a line spectrum with widely spaced lines, the wavelengths of which are well known. Next, the radiation spectrum of the mercury lamp is recorded and decoded and the relationship is established between the wavelengths of its individual lines (peaks on the recorder blank) and divisions of the drum connected to the motor that rotates the prism part of the spectrograph. Based on these data, a dispersion curve of the installation is constructed.

DRL lamps are high-pressure fluorescent mercury discharge lamps with corrected color rendering. Don't be fooled by the definition. The color rendition of DRL lamps is not very decent.

Story

Historically, low-pressure lamps were the first to appear, where the discharge occurred in sodium vapor. It does not mean the process of invention, but the industrial development of lighting devices. Generally speaking, it was Peter Cooper Hewitt who introduced the commercial sense of using discharge lamps for lighting to the industry. And it happened in 1901. Filled with mercury, the lamps seemed so successful to the creator that the researcher organized a company in the new year with the support of George Westinghouse. The enterprises of the latter were engaged in the production of products.

The move seems logical for the simple reason that George Westinghouse, along with Tesla, led the fight for the introduction of alternating current. And he rejoiced at every practical invention, for the operation of which the mentioned kind of electricity was required. The sodium lamp appeared in 1919 thanks to the efforts of Arthur Compton. A year later, borosilicate glass was added to the structure. Characterized by a low coefficient of thermal expansion, it perfectly resisted the aggressive environment of sodium vapor. The practical use of lamps on the streets of cities dates back to the beginning of the 30s (in the Netherlands - from July 1, 1932).

The luminous flux of sodium lamps was 50 lm/W, which was considered a worthy indicator. Despite the specific yellow-orange color of the radiation. In the USSR, the development of low-pressure sodium lamps did not go. Mercury was considered more acceptable. In addition, high-pressure sodium lamps appeared. The described models are characterized by incorrect color rendering. This applies to living objects and humans. The disadvantage was partially overcome in 1938 by introducing low-pressure mercury lamps into industrial production. Key Features:

1. Light output - 85 - 104 lm / W.
2. Service life - up to 60 thousand hours.
3. Perspective emission spectrum.

DRL lamps appeared in the early 50s. Their operational characteristics do not reach those given above (output 45 - 65 lm / W, service life 10 - 20 thousand hours), but acceptable. DRL lamps are used for outdoor and indoor lighting. The next step in the development of discharge lamps was HRVI (high intensity). The key difference was the increased efficiency. In the first samples, the indicator was already 100 lm / W. High pressure sodium lamps outperform the DRL model.

Features of the discharge lamp with corrected color rendering

Bulb brightness

It was said above that individual discharge (and fluorescent) lamps are characterized by low color rendering. The surrounding world becomes slightly distorted, which quickly tires the psyche. An additional factor is the physiological sensitivity of the eyes. It is not the same in the visible spectrum, some people are able to see the aura. But in most individuals, the maximum of susceptibility is at a wavelength of 555 nm (green color). And towards the edges, the sensitivity of the eyes subsides.

Therefore, researchers call for adjusting the power of lamps to the physiological characteristics of a person. As a result, 1 watt at 555 nm is equivalent to 10 at 700 nm. Infrared radiation is not perceived by humans. The brightness is estimated by the luminous flux, which takes into account the effect of each wavelength. The unit of measurement was the lumen, equivalent to a power of 1/683 W for a wavelength of 555 nm. And light output (lm / W) shows what proportion of the power in the light bulb becomes optical radiation. The maximum value reaches 683 lm / W and is observed exclusively at a wavelength of 555 nm.

It is impossible to ignore the unit of illumination - lux. Numerically equal to 1 lm / sq.m. Knowing the luminous flux, the height of the lamp, the angle of its opening, it is possible to calculate the illumination. The parameter for rooms is normalized according to GOST. In light of the foregoing, it is understandable why DRL lamps with corrected color rendering are still found on the market, despite the relatively unenviable characteristics.

Locus is used to evaluate color rendering. This is a figure resembling an inverted parabola, slightly overwhelmed on its left side. In it, the color shows two coordinates from 0 to 1. In order for the lamp to show good color rendering, the position of its integral radiation tends to the center of the locus. Add that raising the color temperature will shift the spectrum from red to violet:

• 2880 - 3200 K - warm yellow;
• 3500 K - neutral white;
• 4100 K - cold white;
• 5500 - 7000 K - daylight.

In this regard, yellow-orange low pressure sodium lamps are considered an unfortunate choice. From them, a chemical imbalance in the retina of the eye causes fatigue. However, remember that the spectrum, not the color temperature, still plays a decisive role: any light bulb is inferior to the Sun. Therefore, in the poor spectrum of a low-pressure sodium lamp (two spectra in the yellow area), objects look black, gray or yellow. This is called color mismatch.

It is customary to characterize the parameter with an index based on a visual comparison of the samples illuminated by a light bulb with a standard. The value falls within the range from 1 (worst case) to 100 (ideal). In practice, it is possible to find a maximum lamp in the range of 95 - 98. This will help you choose a DRL lamp on the counter (typical value is 40 - 70).

Color Correction

A discharge glows in an ionized gas environment. The whole principle of action. The rest is reduced to the conditions for obtaining the burning of the arc between the electrodes. Ionization conditions require an increased voltage, which is no longer needed in the future. Often discharge lamps require a ballast. The atmosphere is filled with an inert gas and a small amount of elastic metal vapors (mercury, sodium, their halides). In the practice of lamps, the following types of discharges are mainly used:

1. Glow - with a low current density at low gas or vapor pressure. The voltage drop across the cathode reaches 400 V. Dark spots are visually visible in the area of ​​the cathode.
2. Arc - with a high current density at various pressures. The voltage drop across the cathode is relatively small (up to 15 V). The low pressure arc column is similar to a smoldering one.
3. High intensity arcs are a specific phenomenon used in spotlights. For example, they were used to detect enemy air targets during the Second World War. It is based on a special mode of operation of a carbon rod, discovered in 1910 by G. Beck.

The spectrum of the mercury discharge lies in the ultraviolet region by 40%. The phosphor transforms this area into a red glow, while most of the purple and blue parts pass freely. The quality of the spectrum correction is determined by the red ratio (it increases with increasing layer thickness, like the price, the required parameters are determined experimentally due to the complexity of the calculation). The mercury burner is made of quartz glass (does not emit gaseous substances during operation), and the outer flask, coated with a phosphor from the inside, is made of ordinary, but refractory. Edison base. Europium-activated yttrium phosphate-vanadate is used as a phosphor. The material detects a luminescence spectrum of four red bands: 535, 590, 618 (max), 650 nm. The optimal mode of operation is achieved at temperatures from 250 to 300 degrees (output time is about a quarter of an hour).

Before application, the phosphor is ground and calcined. Yttrium vanadate phosphate was chosen for a reason, it withstands processing perfectly. The considerable cost is often offset by the joint use with other materials. For example, orthophosphate of strontium-zinc. They better absorb the wavelength of 365 nm, it is possible to achieve acceptable characteristics (taking into account the specifics of application in the field of industrial lighting with an installation height of 3 to 5 meters).

Cases of using magnesium fluorogermanate activated with tetravalent manganese are known. Light output and red ratio (6-8%) are slightly reduced. The optimum temperature regime is set around 300 degrees Celsius. With further heating, the efficiency of the device decreases. The material, in all respects, except for the price, is inferior to yttrium vanadate phosphate: it absorbs part of the violet-blue region of the spectrum, detects a glow spectrum in the far red region (where the eye shows low sensitivity), and loses brightness during processing.

The design usually provides for one or two ignition electrodes, the distance from which to the cathode is relatively small. So an external ballast is not required. In combination with a standard base, a convenient replacement for incandescent bulbs with increased efficiency is obtained. The flask during operation heats up strongly due to the intense absorption of radiation by the phosphor. The calculation of the geometric shape is carried out based on this parameter. On the one hand, it is required that the radiation of the burner falls on the phosphor, on the other hand, the temperature in the operating mode should not exceed the optimum (see above).

The flask is filled more often with argon. It is cheap and introduces little heat loss. 10-15% nitrogen is mixed in to increase the breakdown voltage. The total pressure is approximately equal to atmospheric pressure. The ingress of oxygen (destroys metal parts) or hydrogen (increases the ignition voltage of the arc) is unacceptable. Any burning position is allowed, but horizontal is discouraged. The arc is slightly bent, the quartz glass is in an unfavorable temperature regime. The medium temperature affects the breakdown voltage. In winter, it is more difficult to ignite an arc, mercury settles, and the process takes place in an environment of almost pure argon (for this reason, starting devices sometimes have to be used).

For DRL lamps, the base is relatively hot. The temperature can exceed the boiling point of water. This must be taken into account when choosing a cartridge and a chandelier (lantern) for installing a lamp. It's time to remember the advice of the authors of the patent for the first halogen lamps. The burner temperature is relatively low, but it will easily melt aluminum.

Marking

In domestic practice, the figure after the DRL means the power consumption in watts. Then follows the red ratio: the ratio of the red flux (from 600 to 780 nm) to the total - expressed as a percentage. The development number is put through a hyphen. The red ratio characterizes the color rendition, more than ten are considered good values.

According to the international standard IEC 1231, the ILCOS system is used. These are competitors of the German LBS marking and the pan-European ZVEI. The market is in complete disarray. According to ILCOS:

1. QE stands for the ellipsoid shape of the flask.
2. QR designates a flask with an internal reflective layer, mushroom-shaped.
3. QG stands for spherical flask.
4. QB stands for products with built-in ballast.
5. QBR stands for products with built-in ballast and reflective layer.

Philips has its own way of looking at things, but General Electric doesn't want to hear about both. Actually, it is better to focus on reference books, or read the information on the package. Remember that the plinth is standard and other sizes. The share of production of DRL lamps is constantly decreasing, so it makes no sense to study complex designations in too much detail. And given the entry into the LED market, for home and garden it is better to find something modern and constantly evolving. With regard to efficiency, the dispute will clearly not be decided in favor of discharge lamps, although for some time they successfully precipitated a filament.

To name all types of such light sources in domestic lighting technology, the term "discharge lamp" (RL) is used, which is included in the International Lighting Dictionary approved by the International Commission on Illumination. This term should be used in technical literature and documentation.

Depending on the filling pressure, there are low-pressure radar (RLND), high pressure (RLHP) and ultra-high pressure (RLSVD).

RLND include mercury lamps with a partial pressure of mercury vapor in steady state less than 100 Pa. For RLSVD this value is about 100 kPa, and for RLSVD - 1 MPa or more.

Low-pressure mercury lamps (RLND) High-pressure mercury lamps (RVD)

RVD are divided into lamps for general and special purposes. The first of them, which include, first of all, the widespread DRL lamps, are actively used for outdoor lighting, but they are gradually being replaced by more efficient sodium and metal halide lamps. Special purpose lamps have a narrower range of applications; they are used in industry, agriculture, and medicine.

Radiation spectrum

Mercury vapor emits the following spectral lines used in gas discharge lamps:

The most intense lines are 184.9499, 253.6517, 435.8328 nm. The intensity of the remaining lines depends on the mode (parameters) of the discharge.

Kinds

High pressure mercury lamps type DRL

DRL (D corner R mulberry L luminescent) - the designation of RLVD adopted in domestic lighting technology, in which to correct the color of the light flux, aimed at improving color rendering, phosphor radiation applied to the inner surface of the bulb is used. To obtain light, the DRL uses the principle of constant burning of a discharge in an atmosphere saturated with mercury vapor.

It is used for general lighting of workshops, streets, industrial enterprises and other facilities that do not impose high requirements on the quality of color reproduction and premises without permanent human presence.

Device

The first DRL lamps were made with two electrodes. To ignite such lamps, a source of high-voltage pulses was required. As it was used the device PURL-220 (Starting Device for Mercury Lamps for a voltage of 220 V). The electronics of those times did not allow the creation of sufficiently reliable igniting devices, and the PURL included a gas discharger, which had a shorter service life than the lamp itself. Therefore, in the 1970s. industry has gradually ceased production of two-electrode lamps. They were replaced by four-electrode ones that do not require external igniters.

To match the electrical parameters of the lamp and the power supply, almost all types of radars that have a falling external current-voltage characteristic need to use a ballast, which in most cases uses a choke connected in series with the lamp.

A four-electrode DRL lamp (see the figure on the right) consists of an external glass bulb 1 equipped with a threaded base 2. A quartz burner (discharge tube, RT) 3, which is filled with argon with mercury additive, is mounted on the lamp leg mounted on the geometric axis of the outer bulb. Four-electrode lamps have main electrodes 4 and auxiliary (igniting) electrodes 5 located next to them. Each ignition electrode is connected to the main electrode located at the opposite end of the RT through a current-limiting resistance 6. Auxiliary electrodes facilitate ignition of the lamp and make its operation during the start-up period more stable. The conductors in the lamp are made of thick nickel wire.

Recently, a number of foreign firms have been manufacturing three-electrode DRL lamps equipped with only one ignition electrode. This design differs only in greater manufacturability in production, having no other advantages over four-electrode ones.

Operating principle

The burner (RT) of the lamp is made of a refractory and chemically resistant transparent material (quartz glass or special ceramics), and is filled with strictly metered portions of inert gases. In addition, metal is introduced into the burner, which in a cold lamp has the form of a compact ball, or settles in the form of a coating on the walls of the flask and (or) electrodes. The luminous body of the RLVD is a column of arc electric discharge.

The ignition process of a lamp equipped with ignition electrodes is as follows. When a supply voltage is applied to the lamp, a glow discharge occurs between the closely spaced main and ignition electrodes, which is facilitated by a small distance between them, which is significantly less than the distance between the main electrodes, therefore, the breakdown voltage of this gap is also lower. The appearance in the RT cavity of a sufficiently large number of charge carriers (free electrons and positive ions) contributes to the breakdown of the gap between the main electrodes and the ignition of a glow discharge between them, which almost instantly turns into an arc discharge.

Stabilization of the electrical and light parameters of the lamp occurs 10-15 minutes after switching on. During this time, the lamp current significantly exceeds the rated current and is limited only by the resistance of the ballast. The duration of the starting mode is highly dependent on the ambient temperature - the colder, the longer the lamp will flare up.

The electrical discharge in the burner of a mercury arc lamp produces visible blue or violet radiation, as well as powerful ultraviolet radiation. The latter excites the glow of the phosphor deposited on the inner wall of the outer bulb of the lamp. The reddish glow of the phosphor, mixing with the white-greenish radiation of the burner, gives a bright light close to white.

A change in the mains voltage up or down causes a change in the luminous flux: a deviation of the supply voltage by 10-15% is acceptable and is accompanied by a corresponding change in the luminous flux of the lamp by 25-30%. When the supply voltage drops below 80% of the rated voltage, the lamp may not light up, and the burning one may go out.

When burning, the lamp becomes very hot. This requires the use of heat-resistant wires in lighting devices with mercury arc lamps, and imposes serious requirements on the quality of cartridge contacts. Since the pressure in the burner of a hot lamp increases significantly, its breakdown voltage also increases. The mains voltage is not sufficient to ignite a hot lamp, so the lamp must cool before re-ignition. This effect is a significant drawback of high-pressure mercury arc lamps: even a very short interruption of the power supply extinguishes them, and a long cooling pause is required for re-ignition.

Traditional applications of DRL lamps

Lighting of open areas, industrial, agricultural and warehouse premises. Wherever this is due to the need for great energy savings, these lamps are gradually being replaced by NLVD (lighting cities, large construction sites, high production halls, etc.).

The Osram HWL series (analogue of the DRV) has a rather original design, which has a conventional filament as a built-in ballast, placed in an evacuated cylinder, next to which a separately sealed burner is placed in the same cylinder. The filament stabilizes the supply voltage due to the barretter effect, improves color characteristics, but, obviously, very noticeably reduces both the overall efficiency and the resource due to the wear of this filament. Such RLVDs are also used as household ones, as they have improved spectral characteristics and are included in an ordinary lamp, especially in large rooms (the lowest-powered representative of this class creates a luminous flux of 3100 Lm).

Arc mercury metal halide lamps (DRI)

Lamps DRI (D corner R mulberry with And radiating additives) is structurally similar to DRL, however, strictly metered portions of special additives - halides of certain metals (sodium, thallium, indium, etc.) are additionally introduced into its burner, due to which the light output significantly increases (about 70 - 95 lm / W and above) with a sufficiently good chromaticity of the radiation. Lamps have bulbs of ellipsoidal and cylindrical shape, inside which is placed a quartz or ceramic burner. Service life - up to 8 - 10 thousand hours.

Modern DRI lamps mainly use ceramic burners, which are more resistant to reactions with their functional substance, due to which, over time, the burners darken much less than quartz burners. However, the latter are also not discontinued due to their relative cheapness.

Another difference between modern DRIs is the spherical shape of the burner, which makes it possible to reduce the decline in light output, stabilize a number of parameters and increase the brightness of a "point" source. There are two main versions of these lamps: with E27, E40 socles and soffit - with Rx7S socles and the like.

To ignite DRI lamps, a breakdown of the interelectrode space by a high voltage pulse is necessary. In the "traditional" circuits for switching on these vapor-light lamps, in addition to an inductive ballast choke, a pulse igniter is used - IZU.

By changing the composition of impurities in DRI lamps, it is possible to achieve "monochromatic" glows of various colors (violet, green, etc.). Due to this, DRI is widely used for architectural lighting. DRI lamps with an index of "12" (with a greenish tint) are used on fishing boats to attract plankton.

Arc mercury metal halide lamps with a mirror layer (DRIZ)

Lamps DRIZ (D corner R mulberry with And radiating additives and Z mirror layer) is an ordinary DRI lamp, part of the bulb of which is partially covered from the inside with a mirror reflective layer, due to which such a lamp creates a directed stream of light. Compared with the use of a conventional DRI lamp and a mirror spotlight, losses are reduced due to a decrease in re-reflections and light passages through the lamp bulb. It also results in a high accuracy of focusing the torch. In order for the direction of radiation to be changed after screwing the lamp into the socket, DRIZ lamps are equipped with a special base.

Mercury-quartz ball lamps (DRSH)

Lamps DRS (D angular R mulberry W arc) are arc mercury lamps of ultrahigh pressure with natural cooling. They have a spherical shape and give a strong ultraviolet radiation.

High-pressure mercury-quartz lamps (PRK, DRT)

High pressure mercury arc lamp type DRT (D angular R mulberry T ribbed) are a cylindrical quartz flask with electrodes soldered at the ends. The flask is filled with a metered amount of argon, in addition, metal is introduced into it.