Thorn MBFR Kolorlux Mercury Discharge Reflector

The °Kolorlux MBFR lamps from Thorn Lighting offer all the benefits of standard mercury discharge lamps, but the internal reflector offers two great advantages.

Firstly, the lamps provide good optical control but without the requirement for expensive reflector systems. Whereas competitive lamps traditionally employed a diffuse front window, it is left clear in the Thorn design. This delivers much better optical control with a considerably tighter beam angle, but there is some lack of colour uniformity throughout the illuminated area. However when lamps are used in quantity, as is typically the case with large-scale industrial illumination, there is some overlap between the beams of adjacent lamps which partly cancels this effect.

The second principal advantage of the reflector-style lamps is that optical performance is not restricted by the build-up of dirt or corrosion on reflecting surfaces, as is the case with conventional luminaires. With each new lamp comes a new optical system and there is, of course, no need for expensive cleaning maintenance of the luminaire on a regular basis.

The use of MBFR therefore reduces both capital installation costs, and maintenance / cleaning costs in all industrial applications which can accept the broader polar intensity distribution of this lamp over a high bay luminaire.

Technically, the construction of MBFR is similar to the standard MBF design. It employs the same °Kolorlux yttrium vanadate phosphors as standard lamps, with an undercoat of titanium dioxide before the phosphor layer acting as a reflective surface which also transmits some upward light.
Manufacturer: Thorn EMI
Lamp Power: 400 Watts
Lamp Current: 3.25 Amps
Lamp Voltage: 135 Volts
Cap: E40s/45 Ni Plated + Vitrite
Bulb Finish: Eu:YVO phosphor TiO2 reflector coating
Bulb Type: RD-180 Borosilicate
Overall Length: 300 mm
Light Centre Length: N/A
Electrodes: Backwound tungsten with triple carbonate emitter
Atmosphere: Inner : Argon | Hg Outer : Nitrogen
Luminous Flux: 20,500 lm @ 100 hours 18,000 lm @ 2,000 hours
Luminous Efficacy: 51.3 lm/W @ 100 hours 45.0 lm/W @ 2,000 hours
Colour Temperature & CRI: CCT: 3800K CRI: Ra 35
Chromaticity Co-ordinates: CCx: 0.395 ccy: 0.400
Burning Position Universal
Rated Life: 20,000hrs to 70% survival, 24,000hrs to 50% survival
Factory: Leicester England
Date of Manufacture: September 1988
Original / Present Value: £38.50 (1988) £62.40 (2001)
References: 1) Thorn Lighting Comprehensive Catalogue, UK, 1989/90, p.361
2) Thorn Lighting Discharge Lamps Brochure 1988
3) Thorn Lighting Price List 1988