HQI-T Single Ended Compact Metal Halide
Following on from Osram's pioneering introduction of low wattage metal halide lighting with its double ended lamp, it soon became clear that consumers desired an even more compact light source in this series.  The logical progression was to adopt a smaller single ended arc tube design.  Thorn Lighting had long since been the leader in single ended metal halide lamps having great experience with its short arc CSI and CID products.  Osram was of course the leader in low wattage metal halide products, and the two companies worked on a new project to create a single ended compact metal halide source based on Osram's low wattage technology and Thorn's single ended experience.

The result was a new range of 150W and 70W single ended products launched by both companies, with Osram also offering a 35W version as well. 

The arc tube is essentially based on Thorn's 200W CID short arc lamp, but its shape has been modified in an attempt to create an isothermal design, in which all areas of the surface are at as near a uniform temperature as possible.  This ensures higher temperature operation of the metal halide dose and leads to increased luminous efficacy and better colour rendering.  Electrodes are of solid thoriated tungsten with open-coiled ends, making the arc gap shorter at the tips than the spacing between the leads in the pinch-seal. The metal halide system is different from the double ended variant, being based mainly on tin with additions of sodium and thallium iodides. However colour stability through life remains excellent, owing to the fact that the rate of sodium loss is low. Just like with the double-ended HQI-TS, there is no metal frame wire running alongside the arc tube.
Manufacturer: Osram GmbH
Lamp Power: 75 Watts (SON ballast)
Lamp Current: 0.98 Amps (SON ballast)
Lamp Voltage: 95 Volts (SON ballast)
Cap: G12
Bulb Finish: Clear quartz
Bulb Type: T-25
Overall Length: 85 mm
Light Centre Length: 56 mm
Electrodes: Thoriated tungsten
Inner / Outer Atmosphere: Ar | Hg (Sn,Na,Tl)Ix Outer: Vacuum
Luminous Flux (100 hrs): 5,200lm @ 100 hours
Luminous Efficacy (100 hrs): 69 lm/W @ 100 hours
Colour Temperature & CRI: CCT: 3000K CRI: Ra 80
Chromaticity Co-ordinates: CCx: 0.428 CCy: 0.389
Burning Position: Universal
Rated Life: 6000 hours (to 50% survival and 70% lumens)
Warm Up / Re-strike Time: 4 minutes 10 minutes max.
Factory: Spandau (Berlin), Germany
Date of Manufacture: June 1991
Original / Present Value:
 
References: 1) Osram Lichtprogramm 2002.