Iwasaki SDX White High Pressure Sodium
Iwasaki's SDX line of high pressure sodium lamps deliver an exceptionally stable and high quality white light, which is recognised by lighting designers worldwide as offering the best lighting quality of any sodium lamp. The light colour is virtually identical to that produced by incandescent lamps and it makes a very attractive light source for interior illumination but with 3-5 times greater luminous efficacy. The lamps also emit very little UV radiation and are safe for open fixture use with no protective front glass.

SDX is the direct successors of the earlier "Specialux" high colour rendering lamps, which operate in unsaturated vapour at much higher pressure to broaden the spectrum and deliver exceptional colour rendering. SDX colour control is tighter again, due to a dedicated electronic ballast.

Iwasaki's unique sintered electrode is employed in this lamp, consisting of tungsten and emitter powders packed together and sintered into a solid slug. This electrode is responsible for the low blackening rate of the arc tube and delivers high lumen maintenance as well as extended life for the low wattage lamps. The end seals of the arc tube are made with the company's exclusive plasma sealing technique, in which the niobium tubes protruding from the ceramic arc tube are completely sealed over and fused.

The small arc tube is supported on a thin frame of steel and held in place with nickel tie wires. Also as would be expected from any Japanese lamp, the physical appearance and level of build quality cannot be faulted in any way, with the glassworking in particular showing exceptional attention to detail at every point.
Manufacturer: Iwasaki Electric Co. Ltd.
Lamp Power: 50 Watts
Lamp Current: 1.32 Amps 200Hz Square wave
Lamp Voltage: 45 Volts 1.6-2.3kV Ignition
Cap Type: E26s/25 Ni plated brass + blue glass
Bulb Finish: Clear Borosilicate glass
Bulb Type: T-30 T-9 in eighths/inch
Overall Length: 110 mm 4 5/16 inches
Light Centre Length: 75 mm 3 inches
Arc Length: 9 mm 23/64 inch
Electrodes: Sintered pellet Tungsten-emitter composite
Atmosphere: Na,Hg | Xe Outer: Hard Vacuum
Luminous Flux: 2,500 lm @ 100 hrs 2,400 lm @ 3,000 hrs
Luminous Efficacy: 50.0 lm/W @ 100 hrs 48.0 lm/W @ 3,000 hrs
Colour Temperature & CRI: CCT: 2500K CRI: Ra 82
Chromaticity Co-ordinates: CCx: 0.477 CCy: 0.414
Burning Position: Universal
Rated Lifetime: 6,000 hours to 50% survival
Warm-up & Re-strike Time: 8 minutes 5 minutes max.
Factory: Kakegawa & Saitama Japan
Date of Manufacture: Circa 1988
Original & Present Value: Unknown
References: 1) EYE SDX Technical Booklet, 1995.
2) EYE SDX Technical Bulletin, November 1995.