RLOD#44 (2020.08.19) 1997 Tungsram HgMIG 2000W/S

Introduced during the 1980s, the HgMIG 2000W/S is the first metal halide lamp filled with the NTI mix (i.e., sodium, thallium and indium iodides) that is truly optimized for efficiency. Tungsram managed to increase the lumen efficacy of the original high-voltage 2-kW neutral-white metal halide lamp by 17 % to 105 lm/W, a first for this particular technology, and the source luminance by 45 % to 770 cd/cm². This was achieved by shortening the arc by 30 mm to 120 mm, by using a narrower burner with conical extremities, and with a higher sodium fraction in the fill chemistry. The latter lowers the light color temperature to 3500 K. This optimization requires an operation in the horizontal position within 20° in order to ensure optimal performances, which makes the lamp suitable for a use in cylindrical parabolic luminaires only. Like its predecessor, the HgMIG 2000W/S is provided with an auxilliary electrode which enables a reliable discharge ignition on 380–415 V mains circuits without the need for an electronic ignitor. The design of this lamp remained mostly unchanged throughout its commercial life, which came to an end in the second half of the 2010s.