1,492
edits
Difference between revisions of "Osram HWL"
m
no edit summary
Andrei.boiu (talk | contribs) m (→Suitability) |
Andrei.boiu (talk | contribs) m |
||
| Line 10: | Line 10: | ||
*Integrated internal ballast featuring an incandescent coil (filament) | *Integrated internal ballast featuring an incandescent coil (filament) | ||
*E27 base or E40 base | *E27 base or E40 base | ||
*Soft glass ( | *Soft glass (160 and 250W) or Hard glass (250 and 500W) bulb | ||
*230V operating voltage (highly sensitive to voltage) | *230V operating voltage (highly sensitive to voltage) | ||
*Typical lifetime of 10.000 (most lamps) to 13.000 hours (only 160W lamp) | *Typical lifetime of 10.000 (most lamps) to 13.000 hours (only 160W lamp) | ||
| Line 21: | Line 21: | ||
</div> | </div> | ||
|style="vertical-align:top" | | |style="vertical-align:top" | | ||
[[Image:Philips HPL-N 250W.jpg| | [[Image:Philips HPL-N 250W.jpg|Osram HWL 250W]] | ||
|} | |} | ||
| Line 45: | Line 45: | ||
! Designation !! Base !! Lamp wattage !! Luminous flux !! Colour appearance !! Colour Temperature !! Colour Rendering Index (Ra8) !! Life (to 50% failures) | ! Designation !! Base !! Lamp wattage !! Luminous flux !! Colour appearance !! Colour Temperature !! Colour Rendering Index (Ra8) !! Life (to 50% failures) | ||
|- | |- | ||
| ML | | ML 160W E27 225-235V SLV || E27 || 160 W || 3100 lm || Neutral White || 3600 K || 62 || 10000 hours | ||
|- | |- | ||
| ML | | ML 250W E27 225-235V SG SLV || E27 || 250 W || 5600 lm || Cool White || 3800 K || 58 || 10000 hours | ||
|- | |- | ||
| ML 250W | | ML 250W E40 225-235V HG SLV || E40 || 250 W || 5600 lm || Cool White || 3800 K || 58 || 10000 hours | ||
|- | |- | ||
| ML 500W E40 225-235V HG SLV || E40 || 500 W || 14000 lm || Cool White || 4100 K || 49 || 10000 hours | |||
| ML 500W E40 225-235V HG SLV || E40 || 500 W || | |||
|- | |- | ||
|} | |} | ||
| Line 62: | Line 60: | ||
Generally, mercury vapour lamps were very durable but mixed lights, mercury vapour and tungsten, are quite sensitive. Strong, sudden shocks can damage the internal tungsten filament, permanently affecting the lamp. On each start-up the lamp is highly stressed as the tungsten filament operates at almost double the normal rated current which means that service life is strongly affected by switch on frequency. The lamp is impossible to service if any rupture of the filament occurs. | Generally, mercury vapour lamps were very durable but mixed lights, mercury vapour and tungsten, are quite sensitive. Strong, sudden shocks can damage the internal tungsten filament, permanently affecting the lamp. On each start-up the lamp is highly stressed as the tungsten filament operates at almost double the normal rated current which means that service life is strongly affected by switch on frequency. The lamp is impossible to service if any rupture of the filament occurs. | ||
All the above particular operating issues make the lamp slightly inconvenient to operate, even if the lamp itself is highly attractive to use and install and not an expensive purchase. Failing lamps can be easily determined by the lengthened time of restart in case of power being cut off and then resumed. A longer than typical time and less definite starting after | All the above particular operating issues make the lamp slightly inconvenient to operate, even if the lamp itself is highly attractive to use and install and not an expensive purchase. Failing lamps can be easily determined by the lengthened time of restart in case of power being cut off and then resumed. A longer than typical time and less definite starting after cool-down, meaning more failed attempts at restarting than 1 or 2, point to a worn of lamp that will soon be dead. Of course, as mentioned before, this should be tested with the same straight vertical position. However, as lamps age, they will be more sensitive to voltage, accumulated heat nearby the lamp than newer ones so actual service life can be severely reduced compared with what the datasheet may suggest. | ||
== Greatest features & flaws == | == Greatest features & flaws == | ||
| Line 85: | Line 83: | ||
The pleasant light is suited both as general lighting in homes as well as gardens or workshops. A good selection of lamps can be used if power consumption is not critical and a specific scene or effect is desirable. Unfortunately, especially in small spaces, the lamp can contribute to heating, which may be advantageous as well as undesirable, depending on application. Special care should be taken when cleaning the lamp as vibrations, dirt accumulation and improper handling can easily crack the bulb, especially on soft glass lamps. Any dirt present on the lamp may be trapped longer due to melting and subsequent adhesion to glass. This means that lamp cleaning has to be as thorough and careful as on old tungsten lamps. While the lamp has a very high output when started and slowly reduces on warm-up, with a corresponding change in light colour, it is not unpleasant. At the beginning, most light is output by the internal incandescent filament rather than the mercury discharge. Lamp restart in case of failure occurs in less than 2 minutes and is less unpleasant than on other high pressure discharge lamps. | The pleasant light is suited both as general lighting in homes as well as gardens or workshops. A good selection of lamps can be used if power consumption is not critical and a specific scene or effect is desirable. Unfortunately, especially in small spaces, the lamp can contribute to heating, which may be advantageous as well as undesirable, depending on application. Special care should be taken when cleaning the lamp as vibrations, dirt accumulation and improper handling can easily crack the bulb, especially on soft glass lamps. Any dirt present on the lamp may be trapped longer due to melting and subsequent adhesion to glass. This means that lamp cleaning has to be as thorough and careful as on old tungsten lamps. While the lamp has a very high output when started and slowly reduces on warm-up, with a corresponding change in light colour, it is not unpleasant. At the beginning, most light is output by the internal incandescent filament rather than the mercury discharge. Lamp restart in case of failure occurs in less than 2 minutes and is less unpleasant than on other high pressure discharge lamps. | ||
This type of mercury vapour lamps were popular mostly before the oil crisis that occurred in the 1970s. Many years have passed since use of this lamp was basically non existent, meaning that stocks are not very large. Although the lamp could directly replace even less efficient tungsten or incandescent lamps, this market very rapidly diminished as soon as compact fluorescent lamps with screw bases were made available. These had a much longer life, had no restriction on mounting, were highly energy efficient and had even better colour reproduction. There were few fixtures specifically designed for Osram HWL lamps. They could operate on typical high pressure mercury vapour fixtures but this was uncommon as they | This type of mercury vapour lamps were popular mostly before the oil crisis that occurred in the 1970s. Many years have passed since use of this lamp was basically non existent, meaning that stocks are not very large. Although the lamp could directly replace even less efficient tungsten or incandescent lamps, this market very rapidly diminished as soon as compact fluorescent lamps with screw bases were made available. These had a much longer life, had no restriction on mounting, were highly energy efficient and had even better colour reproduction. There were few fixtures specifically designed for Osram HWL lamps. They could operate on typical high pressure mercury vapour fixtures but this was uncommon as they most likely replaced incandescent lamps in their fixtures. There was a market for street-lighting in France, many decades ago, as the lamp offered a pleasant light and energy was quite cheap. Due to the lamp operating restrictions as well as simple use, free standing or hanging mounting were quite common, even if lighting efficiency was diminished. | ||
== Operation == | == Operation == | ||
| Line 98: | Line 96: | ||
== History == | == History == | ||
ML lamps are slightly adapted high pressure mercury vapour lamps. They were originally designed to address the requirement of better colour reproduction compared with a bare mercury vapour lamp. While they did | ML lamps are slightly adapted high pressure mercury vapour lamps. They were originally designed to address the requirement of better colour reproduction compared with a bare mercury vapour lamp. While they did severely improve red output of the installation, efficiency was also reduced, since this additional light was created less efficiently with the thermal radiation of the internal filament. Until the advent of suitable internal coatings on standard mercury vapour lamps, this mixed light lamp was also easy to use as there was no requirement for complex wiring, mounting and servicing of ballasts as well as lamps. As most light fixtures were using large wattage incandescent lamps, the Philips ML lamps were very easy to retrofit and for many decades this was a simple light upgrade. Of course, there were many improvements on lamp technology but the same benefits were kept along usability and lower maintenance due to less frequent lamp changing. | ||
Internal coatings were introduced on the entire lamp range in the 1980s although they were present even as early as 1950s on these mixed light lamp types. Coating were useful to make the beam pattern more uniform and there were many benefits to having a coating as the two internal light sources had | Internal coatings were introduced on the entire lamp range in the 1980s although they were present even as early as 1950s on these mixed light lamp types. Coating were useful to make the beam pattern more uniform and there were many benefits to having a coating as the two internal light sources had slightly different patterns. Of course, coatings were useful if flourescent powders were used, but this increased the lamp cost and provided small improvements as light absorption, wear had to be very low. Also, light improvement was much reduced compared with a typically sized mercury vapour lamp due to less UV light being generated by the discharge tube. The advent of improved discharge tubes that were made of quartz instead of glass improved efficiency but results were not as large as on standard mercury vapour lamps. Major efficiency increases were, however, centered on lower powered lamps, as they could not be have the required balance of pressure and temperature to achieve optimal results. | ||
Although important, the introduction of internal coatings did not have the same impact as on standard mercury vapour lamps. For many years the lamp had to be specifically designed to | Although important, the introduction of internal coatings did not have the same impact as on standard mercury vapour lamps. For many years the lamp had to be specifically designed to accommodate filaments as well as the heat being released. The coating itself does not contribute much to the light output as the mercury vapour discharge tube is smaller and has less UV output than a typically sized lamp. As a matter of fact, for a typical power rating, around half the wattage is used by the filament and the other half by the mercury vapour discharge tube. This is mostly due to the compromise of achieving a better colour reproduction than a typical standard mercury vapour lamp and this required more useful light released by the incandescent coil. Of course, better efficiency can be achieved with filaments that do not run as hot and with more light output from the mercury vapour discharge but most longtime manufactured lamps, including the Philips ML, aimed at better comfort and had to accept less efficiency. | ||
== Manufacturing specificities == | == Manufacturing specificities == | ||