Powerball HCI-T 70W/WDL Non-Radioactive
In 2010 the European lampmakers faced a severe problem, in the way of toughened regulations on air transport of radioactive products. This principally affected metal halide lamps, which have traditionally made use of a tiny trace of radioactive Krypton-85 in the arc tube fill or Thorium-232 in the electrodes. Also affected were fluorescent starters and all lamps containing glowbottle starters due to their tritium fillings. The problem did not affect American manufacturers, where such regulations had been introduced decades earlier.

Each of these isotopes has a similar function, in that as they naturally decay they facilitate ionisation of the gas filling between the electrodes. Lamps will eventually start without radioactive aids, but must wait for another source of ionisation - for instance until the arc tube is penetrated by a cosmic ray from outer space. For large lamps this is not such a problem, but low wattage arc tubes are so small that it may take several minutes before they happen to catch a cosmic ray. Such a long starting delay is inconvenient.

Ionisation can also be facilitated with high energy UV photons. For many years the Americans had built UV-enhancer glowbottles into the outer envelopes of their lamp. OsramSylvania was the first to integrate the auxiliary UV glowbottle into the pinch-seals of its quartz metal halide lamps, and in 2011 the same principle was applied to this ceramic arc tube. A strip of sharp-edged molybdenum foil is looped around one of the seals and connected to the opposite electrode. It is essential that the foil is kinked to provide good capacitive coupling with the inner electrode. This ionises the gas in the arc tube providing a few UV photons, which then trigger breakdown and lamp ignition.
Manufacturer: Osram GmbH
Lamp Power: 72 Watts
Lamp Current: 0.96 Amps
Lamp Voltage: 95 Volts 5 kV ignition pulse
Cap Type: G12 Ceramic + NPS pins
Bulb Type: T-19 T-6 in eighths/inch
Bulb Finish: Clear UV-Stop Quartz
Electrodes: Single Coil Thoriated tungsten
Arc Length:
Atmosphere: Ar Hg|Dy-Ho-Tm-Tl-Na-Ix Outer: Hard Vacuum
Luminous Flux: 7,300 lm (@ 100h)
Luminous Efficacy: 100.0 lm/W (@ 100h)
Colour Temperature & CRI: CCT: 3000K CRI: Ra88
Chromaticity Co-ordinates: CCx: CCy:
Rated Lifetime: 15,000 hours (to L70F50)
Warm-up & Re-strike Time: 1 minute (to 80% flux) <15 minutes
Burning Position: Universal
Nominal Length: 100 mm 4 inches
Light Centre Length: 56 mm 27/32 inches
Factory: Berlin-Spandau Germany
Date of Manufacture: 2011 December
Original Value:
References: 1) Osram Catalogue, 2012/2013 EU.
2) Osram Datasheet, HCI-T Powerball Lamps, 2013 EU.