Yaming Coloured Metal Halide JLC250 Red

Coloured metal halide lamps have grown significantly in popularity in recent years. However not all colours can be successfully generated. Some colours appear somewhat weak and washed out, and lack saturation. The success of the various colours is depending on the availability of suitable metal halide salts that are able to efficiently radiate the wavelengths of interest.

Blue and green coloured lamps are the most successful, and have been widely available since the 1970s. A strong green colouration may be attained from a thallium iodide lamp, which has high luminous efficacy on account of its radiation being near to the peak sensitivity of the human eye. A saturated blue coloured lamp can be attained quite easily with a dosage of indium bromide in the arc tube.

Orange lamps are also easy to produce when a sodium iodide filling is employed. However the light colour is substantially the same as from a high pressure sodium lamp, thus they are generally offered only in compact lamps where a high pressure sodium alternative is not available. The colour can be shifted to lemon yellow with sodium+thallium.

Red coloured lamps have, to date, not been successfully made - there are few elements suitable for lamps that radiate the longer wavelengths needed for a red lamp. The closest that is available is a pale magenta colour, attained with a lithium, sodium and indium dose. However YaMing in China boldly marketed a Red coloured lamp a few years ago, based on the above chemistry. In fact after testing, its red saturation is found to be inferior to the European magenta lamps. It is no longer available for obvious reasons.

Manufacturer:	Shanghai Yaming Lighting Co. Ltd.
Lamp Power:	250 Watts
Lamp Current:	2.1 Amps
Lamp Voltage:	118 Volts
Cap Type:	E40s/45	Brass, porcelain insulator
Bulb Finish:	Clear	Borosilicate
Bulb Type:	BT-90	BT-28 (in eighths / inch)
Overall Length:	228 mm
Light Centre Length:	130 mm
Arc Length:	35 mm
Electrodes:	Backwound coil	Thoriated tungsten
Inner / Outer Atmosphere:	Ar \| Hg, (Li,Na,In)Ix	Outer: Nitrogen
Luminous Flux:	12,000 lm @ 100 hours
Luminous Efficacy:	48.0 lm/W @ 100 hours
Colour Temperature & CRI:	CCT: 5500K	CRI: Ra 48
Chromaticity Co-ordinates:	CCx: 0.332	CCx: 0.245
Burning Position:	Universal
Rated Lifetime:	5,000 hours	To 50% survival
Warm-up / Re-strike Time:	2 minutes	10 minutes
Factory:	Malu, Shanghai	China
Date of Manufacture:	October 2004
Original / Present Value:	Not known	Not known


References:	1) Philips & Yaming Chinese Catalogue 2003.
	2) Lamp measurement data.