1,492
edits
Difference between revisions of "Osram HQI-T"
m
→Suitability
Andrei.boiu (talk | contribs) |
Andrei.boiu (talk | contribs) m (→Suitability) |
||
| (5 intermediate revisions by the same user not shown) | |||
| Line 30: | Line 30: | ||
== Best retro purpose == | == Best retro purpose == | ||
Metal Hallide lamps are still widely used on commercial, industrial and architectural lighting but in these applications LED lamps are quickly replacing them due to much better performance, lower energy consumption and easy servicing. Light appearance is coll white or daylight, depending on lamp model, with good colour reproduction and low ultraviolet emission. The lamp can be used indoors as well as outdoors, when intense lighting is required as most surrounding look quite pleasing being light with new lamps. With the most common gear, an electromagnetic ballast along with an ignitor, flicker is noticeable. | Metal Hallide lamps are still widely used on commercial, industrial and architectural lighting but in these applications LED lamps are quickly replacing them due to much better performance, lower energy consumption and easy servicing. Light appearance is coll white or daylight, depending on lamp model, with good colour reproduction and low ultraviolet emission. The lamp can be used indoors as well as outdoors, when intense lighting is required as most surrounding look quite pleasing being light with new lamps. With the most common gear, an electromagnetic ballast along with an ignitor, flicker is noticeable. | ||
With adequate care and good ventilation, HQI-T metal hallides can be used vertically, in a freestanding position as mercury vapour lamps but lifetime will be reduced. HQI-T lamps of lower wattages are slightly more sensitive to operating position than higher wattage ones. Lamps age differently and this means that a series of lamps may exhibit different colour intensity and light intensity depending on wear and group replacement should be considered to maintain uniformity. Just as well, lamps should be replaced as soon as light and colour uniformity is affected, as old lamps present a higher risk of catastrophic failure. | With adequate care and good ventilation, HQI-T metal hallides can be used vertically, in a freestanding position as mercury vapour lamps but lifetime will be reduced. HQI-T lamps of lower wattages are slightly more sensitive to operating position than higher wattage ones. Lamps age differently and this means that a series of lamps may exhibit different colour intensity and light intensity depending on wear and group replacement should be considered to maintain uniformity. Just as well, lamps should be replaced as soon as light and colour uniformity is affected, as old lamps present a higher risk of catastrophic failure. | ||
Overall, this range of lamps is moderately successful for retro purposes as the lamps are quite efficient and have a great variety of wattages and colour designations. Colour rendering is also very good, but only for certain lamps and wattage ratings, so careful analysis of datasheets is recommended before purchase and installation. Fixtures must be designed to house this type of lamp, meaning that a lone lamp is not a good choice and a complete system must be found especially in the case of lower powered lamps that use the bi-pin base as they are specialist items. | Overall, this range of lamps is moderately successful for retro purposes as the lamps are quite efficient and have a great variety of wattages and colour designations. Colour rendering is also very good, but only for certain lamps and wattage ratings, so careful analysis of datasheets is recommended before purchase and installation. Fixtures must be designed to house this type of lamp, meaning that a lone lamp is not a good choice and a complete system must be found especially in the case of lower powered lamps that use the bi-pin base as they are specialist items. | ||
| Line 107: | Line 103: | ||
== Review == | == Review == | ||
These metal hallide lamps are well suited for indoor lighting due to their moderately high power rating and good colour reproduction. Although outdoor lighting is entirely possible, especially for higher power rated lamps | These metal hallide lamps are well suited for indoor lighting due to their moderately high power rating and good colour reproduction. Although outdoor lighting is entirely possible, especially for higher power rated lamps. Large wattage fixtures were very popular especially for flood lighting with boxy, asymmetric or symmetric lighting patterns. The most popular power ratings were 250 and 400 Watss. The lamp itself fares well in terms of light output but the point light source nature of the lamp relegates it to accent or directional rather than general lighting. | ||
Exterior lighting is a good application as most gardens and outside areas are well showcased. The lamps themselves do release some heat meaning that closed fixtures are not well suited if not specifically built for this purpose. Care should be taken when using these metal-hallide lamps as they are sensitive to the operating position especially when inside enclosed fixtures. Compact, boxy symmetric and asymmetric fixtures were popular. Improper heating of lamp can destroy it prematurely and present a safety hazard so special precaution should be exercised. Even if lamp warm up time is low, achieving high output quite quickly, they are slow to restart, 10 minutes pauses not being uncommon. | |||
The lamp's performance is | The lamp's performance is improved compared with typical metal hallide lamps, since very high colour rendering is available on some lamps. Unfortunately, the datasheet is highly convoluted as lamps with different bases, colour renderings and white appearance are present in the same product range. Lamps that have a daylight colour appearance have very high colour rendering index for a quartz metal hallide lamps but they suffer the same lumen output degradation as cool white lamps. Overall, cool white and daylight colour appearance lamps have the best light output stability during service life. Of course, compared with ceramic metal hallide lamps, HQI lamps are faring slightly better than average but they are still lower performing than ceramic lamps. | ||
== Operation == | == Operation == | ||
These lamps are somewhat better suited for frequent switching but starting is still a major stress. They need less than two minutes to reach maximum light output and less than that to restart after being turned off. The light colour and output changes from start-up to normal operation from white to orange. White light at startup and then greenish light midway to warm-up suggests mercury is also used on the lamp. This slightly improves colour rendering but affects slightly reduces lamp life while the ones that do no change colour are either new or do not use mercury at all have a yellower light appearance. Lamps without mercury are more difficult to start but they have longer lifetimes and slightly higher efficiency. | These lamps are somewhat better suited for frequent switching but starting is still a major stress. They need less than two minutes to reach maximum light output and less than that to restart after being turned off. The light colour and output changes from start-up to normal operation from white to orange. White light at startup and then greenish light midway to warm-up suggests mercury is also used on the lamp. This slightly improves colour rendering but affects slightly reduces lamp life while the ones that do no change colour are either new or do not use mercury at all have a yellower light appearance. Lamps without mercury are more difficult to start but they have longer lifetimes and slightly higher efficiency. | ||
The lamp requires a conventional or electro-magnetic gear of the same power output as the lamp, connected in series with a lamp and an ignitor that must be connected as is required in the circuit. Connecting the lamp directly to mains damages it instantly as there is no current limitation. Improper connection of the ignitor is also dangerous and proper care must be exerted during installation and servicing. A power factor capacitor that has a specific value might be used to correct the power factor and current requirements on the circuit. The lamp itself is not influenced by the presence or absence of this capacitor. When used sparingly in homes or some premises where not a lot of these lamps are located, power factor correction is not important but large industrial or commercial clients were required to maintain a specific power factor due to electricity distribution contracting. | The lamp requires a conventional or electro-magnetic gear of the same power output as the lamp, connected in series with a lamp and an ignitor that must be connected as is required in the circuit. Connecting the lamp directly to mains damages it instantly as there is no current limitation. Improper connection of the ignitor is also dangerous and proper care must be exerted during installation and servicing. A power factor capacitor that has a specific value might be used to correct the power factor and current requirements on the circuit. The lamp itself is not influenced by the presence or absence of this capacitor. When used sparingly in homes or some premises where not a lot of these lamps are located, power factor correction is not important but large industrial or commercial clients were required to maintain a specific power factor due to electricity distribution contracting. | ||
== Suitability == | == Suitability == | ||
HQI-TS lamps are a good choice for directional lamp fixtures. If a fixture in good enough condition is found, the lamp offers good light output that could make it useful on interior as well as exterior applications. The most popular lamp wattage seems to be the 70W type, as it was powerful and compact enough to justify the purchase of a fixture that has an elliptical light beam. Garden lighting is not the best application choice as the lamps are not as suited as the 250W and 400W types offer much higher outputs. Indoor lighting is also limited since use in living rooms is not entirely attractive as flicker is present with conventional lamp gears and the lack of hot or quick restart and average lamp performance does not justify the much costlier electronic lamp gear. | HQI-TS lamps are a good choice for directional lamp fixtures. If a fixture in good enough condition is found, the lamp offers good light output that could make it useful on interior as well as exterior applications. The most popular lamp wattage seems to be the 70W type, as it was powerful and compact enough to justify the purchase of a fixture that has an elliptical light beam. Garden lighting is not the best application choice as the lamps are not as suited as the 250W and 400W types offer much higher outputs. Indoor lighting is also limited since use in living rooms is not entirely attractive as flicker is present with conventional lamp gears and the lack of hot or quick restart and average lamp performance does not justify the much costlier electronic lamp gear. | ||
These type of lamps were used for lighting exterior areas especially in the case of higher powered lamps while the most frequent application of low powered ones was indoor accent lighting. The lamp was relatively affordable (for a metal hallide lamp) and small sized, having a successful niche until LED lamps appeared. Since they are very compact light sources it should be noted that heat output is very high, making the lamp unsuitable for open-air operation, especially on lower power ratings, seriously limiting flexibility. While both high pressure mercury vapour and high pressure sodium gear and fixtures can be used, the lamp works closer to designed parameters when used with inductive ballasts for sodium high-pressure vapour lamps and a suitable ignitor added on the circuit as required. | |||
Lower rated power output gears can be used, but it is not recommended as colour reproduction and lamp lifetime will be reduced while higher powered ones damage the lamp due to over-stressing and is highly dangerous. Used lamp gears might work but old lamps are never desirable as they degrade much quicker than mercury vapour and sodium lamps. Rusted ballast may still operate but are a potential hazard while old, used lamps, may not have much useful life left and they may already exhibit some colour light emission issues. New old-stock lamps are the best choice, if available. | Lower rated power output gears can be used, but it is not recommended as colour reproduction and lamp lifetime will be reduced while higher powered ones damage the lamp due to over-stressing and is highly dangerous. Used lamp gears might work but old lamps are never desirable as they degrade much quicker than mercury vapour and sodium lamps. Rusted ballast may still operate but are a potential hazard while old, used lamps, may not have much useful life left and they may already exhibit some colour light emission issues. New old-stock lamps are the best choice, if available. | ||