ConstantColor CMH MR16 Spot

Precisely three years after Sylvania's invention of BriteSpot MR16 metal halide lamp, GE announced its own version with the addition of ceramic arc tube technology, and in a still lower rating of 20 Watts. Made possible through extreme miniaturisation of both the ceramic arc tube and its outer jacket, GE achieved what was previously considered to be impossible in the compact MR16 dimensions.

From the technological standpoint the GE arc tube has a very elegant design, making use of the company's innovative second generation 3-piece arc tube. This employs injection-moulded ceramic end plugs having a large pocket in which the electrode is located. When sintered into the arc tube body the effect is to increase the wall thickness of the ceramic at the tube ends. This is the region where molten metal halide salts generally reside during lamp operation, and where corrosion of the ceramic wall is greatest. Traditionally the arc tube wall must be thick so that during life, corrosion is never able to penetrate all the way through. The thicker tube does absorb some light though, and takes a long time to run up and cool down. The innovative GE design affords adequate protection in the corrosion area, but permits more light to pass through the thin central portion and a run-up time of just 72 seconds.

The arc tube is housed in a tiny quartz outer jacket of just 12mm external diameter, under vacuum atmosphere so as to protect the arc tube seals. A getter stip of zirconium/aluminium material is also present. The reflector is aluminised and of unusual form, so as to situate the focal point at the arc tube position. The long seals of the arc tube mean that a conventional reflector would not be so efficient.
Manufacturer: GE Lighting
Lamp Power: 20 Watts
Lamp Current: 0.215 Amps
Lamp Voltage: 90 Volts
Cap Type: GX10 Steatite Ceramic
Bulb Finish: Aluminised Reflector Clear Lens
Bulb Type: MRC-51 mm MRC-16 eighths/inch
Overall Length: 54.5mm 11 1/4 inches
Light Centre Length: N/A
Arc Length: 3.35mm 1/8 inch
Electrodes: Single coil tungsten
Atmosphere: Ar-Kr85|Hg,(Dy,Ho,Tm,Tl,Na)Ix Outer: Hard Vacuum
Beam Distribution: 12° to 50% Peak 9000 cd
Luminous Flux: 1,000 lm @ 100 hrs
Luminous Efficacy: 50.0 lm/W @ 100 hours
Colour Temperature & CRI: CCT: 3000K CRI: Ra 82
Chromaticity Co-ordinates: CCx: 0.435 CCy: 0.400
Burning Position: Universal
Rated Lifetime: 9000 hours to 50% survival
Warm-up & Re-strike Time: 4 minutes 10 minutes
Factory: Leicester (UK) & Budapest (Hungary)
Date of Manufacture: February 2006 Date Code 0206
Original & Present Value:
References: 1) GE Lighting Brochure: ConstantColor CMH MR16, 2006
2) GE Lighting Brochure: ConstantColour CMH 20W, 2006
3) Lighting Equipment News, April 2006