Mercury Arc Lamp, 500 W, 1.1 x 4.1 mm Effective Arc Size

The 6285 Mercury Arc Lamp contains an exactly measured amount of mercury and either argon gas or xenon which acts as a starter gas as the mercury vaporizes. This 500 watt Hg lamp has a 1.1 x 4.1 mm effective arc size. When the lamp is cold, the gas pressure inside is lower than atmospheric and you can see small globules of mercury inside the lamp. When the lamp runs, this mercury vaporizes and reaches pressures of up to 75 bar. So, these lamps pass from being a rare gas lamp to a mercury lamp. During the five to ten minute transition phase, the lamps run at a higher than normal current and the anode must be at the bottom to ensure proper vaporization of the mercury. Some mercury lamps have a reflective coating on part of the bulb. This speeds the transition phase and improves the thermal distribution. Because the bulb temperature influences the mercury pressure significantly, these lamps are sensitive to airflow over the bulb. Strong mercury lines through the visible and ultraviolet dominate the output spectrum of these lamps. A continuum in the infrared persists to 2.5 μm and beyond. The strong ultraviolet output has led to the use of these lamps for many photochemical processes including lithography and curing. The intense lines are very useful for monochromatic irradiation for fluorescence spectroscopy. Individual lines may be isolated using filters or a monochromator. This lamp is compatible with the 66162 Socket Adapter (not included).