Difference between revisions of "Osram HQI-T"

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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.
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, 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.


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.