Reflux High Pressure Sodium with Reflector
The innovative concept of a side-reflector lamp for streetlighting applications dates back to the 1950's, when Elenbaas of Philips produced a number of 400W mercury vapour lamps of essentially the same design as is illustrated here. However the project was not pursued and lamps of that type never became commercially available.

It was not until 1995 when Russian firm Reflux decided to investigate the idea once again that it was turned into a finalised product ready for the market. Reflux employed skilled Russian optical engineers to come up with a reflector shape which could be moulded in glass, and would deliver a beam profile suitable for streetlighting applications while also satisfying other requirements such as not reflecting infra-red rays back onto the sodium arc tube which would otherwise overheat it and lead to short lamp life. The special batwing-shape reflector can be seen in the end view of the lamp and two models are available, to deliver a broad or a narrow light distribution. A special mounting frame locks the arc tube at the optimum position in the mirror, and a special rotatable cap allows alignment of the lamp.

The principal advantage of the Reflux lamp is that it lowers streetlighting hardware costs, since no optics or luminaire are required. The hard glass bulb is weatherproof and only a simple O-ring seal is required to keep rain away from the cap. Furthermore a brand new mirror is installed with every lamp and being sealed, it cannot deteriorate so lantern cleaning maintenance can be eliminated. The optical efficiency lamp is more than 95% and altogether it represents a much more efficient and well controlled street-lighting system is possible with standard lamps and lanterns.
Manufacturer: Reflux
Lamp Power: 250 Watts
Lamp Current: 3.0 Amps
Lamp Voltage: 100 Volts
Cap Type: EX40s/60x47 Ni plated brass + porcelain
Bulb Finish: Half Aluminised Borosilicate glass
Bulb Type: BRT-122 BRT-37 in eighths/inch
Overall Length: 320 mm 12½ inches
Light Centre Length: N/A
Arc Length:
Electrodes: Backwound thoriated Barium Calcium Tungstate
Atmosphere: Na,Hg | Xe Outer: Hard Vacuum
Luminous Flux: 26,000 lm @ 100 hours
Luminous Efficacy: 104.0 lm/W @ 100 hours
Colour Temperature & CRI: CCT: 1900K CRI: Ra 25
Chromaticity Co-ordinates: CCx: 0.542 CCy: 0.415
Burning Position: Universal
Rated Lifetime: 24,000 hours to 50% survival
Warm-up & Re-strike Time: 5 minutes 15 minutes max.
Factory: Moscow Russian Federation
Date of Manufacture: July 2003
Original & Present Value: Unknown
References: 1) Communication with Reflux, Moscow, 2003.