Difference between revisions of "Osram HQI-T"

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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.