Philips MasterColour Elite CDM-TC 35W/930

In 2007 Philips re-launched its 2nd generation ceramic metal halide technology, Mastercolour Elite, which had previously been introduced in 2005 but was quickly witdrawn due to severe reliability problems encountered with hotter luminaires.

The original Elite lamps retained Philips' 5-piece cylindrical arc tube, but with dramatically reduced dimensions. The resulting increase in wall loading, which would normally destroy such a lamp, was enabled by the addition of 25-35% calcium iodide to the usual rare earth, sodium and thallium halide dose. This reduced the rate of corrosion of the ceramic arc tube. Meanwhile a trace of oxygen emanating from a calcium oxide dispenser initiated a tungsten-halogen cycle to prevent wall blackening and improve lumen maintenance. The smaller and hotter arc tube boosted the colour rendering index above 90, and luminous flux by about 7%, and it was originally claimed that Elite lamps could be dimmed to 60% of rated power and luminous flux. Unfortunately Elite was hampered by quality problems, and became better known as Delete after being withdrawn from sale for 2 years of redevelopment.

The re-launched Elite lamp featured here employs a novel injection-moulded 2-piece cylindrical arc tube, originally patented (but not used) by OsramSylvania. This allows the arc ends to be made much thinner, improving thermal uniformity, light extraction, efficacy, cold spot temperature and accelerating the run-up time and hot-restrike delay. This lamp delivered many of the original promises, notably an impressive boost in efficacy, life and colour rendering. However it is restricted to non-horizontal operation, and the dimming capability was removed - that feature not being re-introduced until the arrival of the Elite LightBoost lamp of 2010.
Manufacturer: Philips Lighting
Lamp Power: 39 Watts
Lamp Current: 0.98 Amps
Lamp Voltage: 85 Volts 5 kV ignition pulse
Cap Type: G8.5 Quartz + Moly pins
Bulb Type: T-15 T-4¾ in eighths/inch
Bulb Finish: Clear UV-Stop Quartz
Electrodes: Single Coil Thoriated tungsten
Arc Length: 4.3 mm
Atmosphere: ArKr85|Hg+(DyHoTmNaTlCa)Ix Outer: Hard Vacuum
Luminous Flux: 3,500 lm (@ 100h)
Luminous Efficacy: 89.7 lm/W (@ 100h)
Colour Temperature & CRI: CCT: 3000K CRI: Ra=90+
Chromaticity Co-ordinates: CCx: 0.434 CCy: 0.396
Rated Lifetime: 12,000 hours (to L80F50)
Warm-up & Re-strike Time: 3 minutes (to 90% flux) <15 minutes
Burning Position: Vertical ± 60°
Nominal Length: 85 mm 43/8 inches
Light Centre Length: 52 mm 2 inches
Factory: Turnhout Belgium
Date of Manufacture: 2007 August Date Code: H7
Original Value: €64.00 (2008)
References: 1) Philips Lamp Catalogue, 2008 NL.
2) Philips OEM Lamp Catalogue, 2009 UK.
3) Elite: The Second Coming, J.D. Hooker, Lighting Magazine UK, February 2008 pp.37-38.
4) Ceramic Metal Halide: The Next Generation, J.D. Hooker, Lighting Equipment News UK, June 2005, pp.14-15.
5) International Patent WO2003/060949, Metal Halide Lamp, J.Lunter & J.H.VanDerVeen, Priority 15-Jan-2002.
6) US Patent 6,004,503, Method of making a ceramic arc tube for metal halide lamps, J.T.Neil (OsramSylvania), Priority 02-Oct-1998.