Philips HPL Deluxe 400W
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' arsenate phosphors in an improved HPL lamp having 7.5-9% red. This was again superseded in 1968 (HPL-N) based on Sylvania's 1964 invention of the vanadate phosphors, featuring 11% red, 10% higher efficacy and a whiter light on the blackbody locus. Philips later made a further improvement by replacing part of the vanadium with phosphorus and boron to achieve 12-13% red.

The HPL-Deluxe lamp was developed in 1972-73 to satisfy market desires for a warmer colour for indoor lighting. It delivers 3300-3700K with 14-16% red (depending on power). The principal difference is its coarse grained yttrium vanadate, 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 light 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 / Dijon 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, pp.11-12.
2) Philips Training Course HTO High Pressure Gas Discharge Lamps, pp.35-36.
3) Philips NL Compact Ligting Catalogue, April 1981.
4) Philips UK Comprehensive Catalogue, 1982.
5) Lamp measurement.