Philips MasterColour Elite CDM-T 70W/930
In 2005 Philips introduced its 2nd generation ceramic metal halide technology, MasterColour Elite, a major improvement beyond the original CDM lamp of 1994. Whereas competitors chose mechanically-based improvements such as GE's 3-piece injection moulded arc tubes, and Osram's rounded Powerball arc tubes, CDM Elite marked the first notable performance breakthroughs based on a new lamp chemistry.

This lamp retains Philips' original 5-piece cylindrical ceramic arc tube, but with dramatically reduced dimensions - the 70W model being similar to the traditional 35W size. Ordinarily such an increase in wall loading would result in short life due to accelerated corrosion of the ceramic by the rare earth halide salts, along with thicker tungsten deposits from the electrodes leading to reduced light transmission. As detailed in International Patent WO2003/060949 the addition of 25-35% calcium iodide reduces the rate of corrosion, while a small trace of calcium oxide facilitates a tungsten-halogen cycle to prevent blackening.

This allows a reduction in arc tube volume, and the resulting increase in wall loading boosts the colour rendering index above 90, and luminous flux by about 7%. Moreover the hotter arc tube can be dimmed to about 60% of rated power while holding the colour temperature constant and CRI above 75. As such, combined with a new electronic ballast, CDM Elite became the worlds first dimmable metal halide system. Unfortunately it was hampered by quality problems, and Elite became known as Delete as it was swiftly withrawn from the market for a painfully long 2 years of redevelopment. The 2nd generation CDM Elite was eventually re-launched in 2007, although regrettably without dimming capability.
Manufacturer: Philips Lighting
Lamp Power: 73 Watts
Lamp Current: 0.98 Amps
Lamp Voltage: 90 Volts 5 kV ignition pulse
Cap Type: G12 Ceramic + NPB pins
Bulb Type: T-19 T-6 in eighths/inch
Bulb Finish: Clear UV-Stop Quartz
Electrodes: Single Coil Thoriated tungsten
Arc Length: 6.0 mm
Atmosphere: ArKr85|Hg+(DyHoTmNaTlCa)Ix Outer: Hard Vacuum
Luminous Flux: 7,100 lm (@ 100h)
Luminous Efficacy: 97.3 lm/W (@ 100h)
Colour Temperature & CRI: CCT: 3150K CRI: Ra=93, R9=50
Chromaticity Co-ordinates: CCx: 0.425 CCy: 0.403
Rated Lifetime: 12,000 hours (to L90F50)
Warm-up & Re-strike Time: 2 minutes (to 80% flux) <15 minutes
Burning Position: Universal
Nominal Length: 100 mm 4 inches
Light Centre Length: 56 mm 27/32 inches
Factory: Turnhout Belgium
Date of Manufacture: 2005 April Date Code: D5
Original Value: Engineering Sample
 
References: 1) Philips Lamp Catalogue, 2005/2006 UK.
2) Mastercolour 2nd Generation, Philips Lighting Presentation, March 2005.
3) Ceramic Metal Halide: The Next Generation, J.D. Hooker, Lighting Equipment News UK, June 2005, pp.14-15.
4) International Patent WO2003/060949, Metal Halide Lamp, J.Lunter & J.H.VanDerVeen, Priority 15-Jan-2002.