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HPL-Comfort High Colour Rendering Lamp |
In general two different lines of research were followed, to create either lamps having better colour rendering properties, or lamps delivering a higher luminous flux. The types with increased luminous efficacy comprised orthophosphate type materials, which added green light to the spectrum and to which the eye is particularly sensitive. Colour rendering left rather a lot to be desired though!
The initial types with improved colour were realised through developments in materials such as yttrium borate, which has enhanced red emission. However, lamps with such materials have rather poor luminous efficacies.
Philips aimed to overcome this issue by using the newer red-enhanced phosphors in combination with others which contributed to the orange part of the spectrum. The result was the HPL-Comfort lamp, which has both a lower colour temperature and a higher efficacy. Crucially its chromaticity lies on the blackbody locus so the light output is a good white.
The phosphor blend in this lamp is believed to comprise yttrium phosphate-vanadate plus a cerium activated YAG phosphor. The latter material is stimulated by blue light rather than UV, the blue absorption being responsible for the slight yellowish appearance of this lamp. Ordinarily YAG phosphors generate green light but on account of the high bulb wall temperature its output is shifted to orange here.
| Manufacturer: | Philips Lighting | |
| Lamp Power: | 80 Watts | |
| Lamp Current: | 0.80 Amps | 1.20A staring current |
| Lamp Voltage: | 115 Volts | |
| Cap: | E27s/27 | Nickel plated brass |
| Bulb Finish: | Phosphor Coated | Y(P,V)O4: Eu + YAG: Ce |
| Bulb Type: | E-70 | Soda lime |
| Overall Length: | 155 mm | |
| Light Centre Length: | N/A | |
| Electrodes: | Backwound thoriated | Double carbonate emitter |
| Inner / Outer Atmosphere: | Inner : Ar | Hg | Outer: Pure Nitrogen |
| Luminous Flux: | 4,000 lm @ 100 hours | |
| Luminous Efficacy: | 50 lm/W @ 100 hours | |
| Colour Temperature & CRI: | CCT: 3500K | CRI: Ra 57 |
| Chromaticity Co-ordinates: | CCx: 0.40 | CCy: 0.38 |
| Burning Position: | Universal | |
| Rated Life: | 28,000 hours to 50% survival | |
| Warm Up / Re-strike Time: | 5 minutes | |
| Factory: | Turnhout, Belgium | |
| Date of Manufacture: | October 1993 | |
| Original / Present Value: | £16.06 (1995) | £18.99 (2002) |
