Philips HPL Deluxe 400W
The Philips developments in mercury fluorescent lamps began in 1937 with the HPL300, employing sulphide phosphors to increase red ratio from 1% to 4%. In 1950 these were replaced by Philips' own arsenate phosphors in an improved HPL lamp having 7.5-9% red. This was again superseded in 1964 (HPL-N) following Sylvania's invention of the vanadate phosphors, which feature 11% red ratio, 10% higher efficacy and a whiter light on the blackbody locus. Philips later made a further improvement of its own by replacing part of the vanadium with phosphorus and boron to achieve 12-13% red.

The HPL-Deluxe lamp featured on this page was developed by Philips in 1972-73 and satisfied market desires for a warmer colour temperature lamp for indoor lighting. It delivers 3300-3700K with 14-16% red (depending on wattage). The principal difference is that it employs a coarse grained yttrium vanadate phopshor, the average particle size being increased from 1.8 to 6.8 microns. Owing to the fact that there are fewer boundaries between individual grains, scattering losses are reduced and efficacy increases. Deluxe lamps partially offset this by employing a coating three times thicker than normal, and due to the greater phosphor weight a greater conversion of the mercury spectrum into red wavelengths can be effected. A small improvement is achieved with activators of Terbium and Gadolinium in addition to the usual Europium.

One small drawback of this approach is that the net light colour sits just below the blackbody locus and is slightly pinkish. In 1983 this problem was solved in the HPL-Comfort lamps which feature a blend of the former deluxe phosphor with Ce:YAG, whose small blue emission corrects the colour point back onto the blackbody locus. This development swiftly rendered the HPL-Deluxe lamps obsolete.
Manufacturer: Philips Eclairage France
Lamp Power: 400 Watts
Lamp Voltage: 140 Volts
Lamp Current: 3.23 Amperes
Cap Type: E40/45 Nickel Plated Brass
Bulb Type: ED-120 ED-37 in eighths/inch
Bulb Finish: YVO4:Eu,Tb,Gd Borosilicate
Electrodes: Backwound Tungsten BaCO3-CaCO3-Y2O3 emitter
Arc Length: 72 mm 2 13/16 inches
Atmosphere: Hg 77mg + Ar 23 torr Outer: Nitrogen
Luminous Flux: 24,000 lm @ 100h
Luminous Efficacy: 60 lm/W @ 100h
Colour Temperature & CRI: CCT: 3700K CRI: Ra 50
Chromaticity Co-ordinates: CCx: 0.397 CCy: 0.392
Rated Lifetime: 24,000 hrs to 50% survival
Warm-up & Re-strike Time: 4' to 80% flux
Burning Position: Universal  
Overall Length: 282±10 mm 11 1/8 inches
Light Centre Length: 142 mm 5 5/8 inches
Factory: Chalon-sur-Saône France
Date of Manufacture: January 1983 A3
Original / Present Value: Unknown  
References: 1) Philips Training Manual MTO Turnhoutlampen, Hogedruk-Kwiklampen, Van der Stap & Goethals, 1986.
2) Philips NL Compact Ligting Catalogue, April 1981.
3) Philips UK Comprehensive Catalogue, 1982.
4) Lamp measurement.