New HPS lamp not in Europe
New HPS lamp not in Europe
During summer 1994, Osram-Sylvania launched a high-pressure sodium lamp in North America in which the mercury content had been cut by 97%. The lamp is intended for direct retrofit in existing luminaires, and provides a more environmentally sound alternative to the traditional HPS lamps.
The manufacturer claimed a ten-percent gain in efficiency and to have overcome the problem with on-and-off cycling at the end of the lamp's life. (See Drastic cut in mercury, IAEEL Newsletter 3/94). The lamp is reported to sell very well in the US and is available in several wattages.
In autumn 1994 the lamp was performance tested for European conditions, Osram claimed. However, Osram is reported to have had difficulty in adjusting the lamp for use in the European 230-volt system, owing to a slight fire hazard posed by lamps when operated with some very old types of ballasts. This risk occurs close to the end of the lamp's life when the amount of available mercury drops below a critical point. The current in the ballast can then increase dramatically, and the ballast can get so hot that it starts to burn.
(Note: This lamp is not to be confused with Osram's new non-mercury HPS lamp, intended for outdoor use with special ballasts.) See also:
Mercury: a Broader Perspective (IAEEL 3/93)
Mercury and Lighting: Managing the Problem, IAEEL 3/93)
More on mercury (IAEEL 1/94)
Drastic cut in mercury (on low-mercury HPS lamps; IAEEL 3/94)
0% mercury retrofit HPS (IAEEL 1/95)