Experimental Sulfur Lamp
date: label: Date made
content: ca 1990
label: date made
content: ca. 1990
name: label: maker
content: Ury, Michael G.
notes: label: Description
content: New lighting inventions occasionally appear from unexpected directions. The development of this microwave-powered lamp provides a case in point. In 1990 Fusion Systems was a small company with a successful, highly specialized product, an innovative ultraviolet (UV) industrial lighting system powered by microwaves.
label: Description
content: Discharge lamps typically use electrodes to support an electric arc. Tungsten electrodes are most common, so materials that might erode tungsten can't be used in the lamp and care must be taken to not melt the electrodes. Fusion's lamp side-stepped this problem by eliminating electrodes entirely. Microwave energy from an external source energized the lamp. This opened the way for experiments with non-traditional materials, including sulfur.
label: Description
content: During the 1980s engineer Michael Ury, physicist Charles Wood, and their colleagues experimented several times with adapting their UV system to produce visible light without success. In 1990, they tried placing sulfur in a spherical bulb instead of a linear tube. Sulfur could give a good quality light, but did not work well in the linear tube. Other elements only gave marginal results in the spherical bulb. But when they tested sulfur in the spherical lamp they found what they hoped for: lots of good visible light with little invisible UV or infrared rays.
label: Description
content: They began setting up "crude" lamps like this one (one of the first ten according to Ury) in order to learn more about the new light source. In the mid-1990s Fusion began trying to sell their sulfur bulbs with limited success. The lamp rotated at 20,000 rpm so that the temperature stayed even over the surface, and a fan was needed for cooling. The fan and spin motor made noise and reduced energy efficiency of the total system. Then they found that the bulbs lasted longer than the magnetrons used to generate the microwaves that powered them. Finding inexpensive magnetrons proved too difficult, and the company stopped selling the product in 2002.
label: Description
content: Lamp characteristics: A quartz stem with notch near the bottom serves as the base. The notch locks the lamp into its fixture. The sphere has an argon gas filling, and the yellow material is sulfur condensed on the inner lamp wall. The pattern of condensation indicates lamp was burned base-down. Tipless, G-shaped quartz envelope.
place: label: Place Made
content: United States: Maryland, Rockville
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Energy & Power
label: See more items in
content: Industry & Manufacturing
label: Exhibition
content: Lighting a Revolution
label: Exhibition Location
content: National Museum of American History
publisher: label: Related Publication
content: Turner, B. P.; Ury, M. G.; Leng, Y.; Love, W.G.. Sulfur Lamps -- Progress In Their Development
label: Related Publication
content: Lighting A Revolution exhibition website
label: Related Web Publication
content: http://americanhistory.si.edu/lighting/
creditLine: label: Credit Line
content: from Fusion Lighting, thru Michael G. Ury
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1992.0467.01
label: catalog number
content: 1992.0467.01
label: accession number
content: 1992.0467
objectType: label: Object Name
content: microwave lamp
label: Object Name
content: discharge lamp
physicalDescription: label: Physical Description
content: glass (overall material)
label: Physical Description
content: sulfur (overall material)
label: Physical Description
content: argon (overall material)
label: Measurements
content: overall: 7 3/4 in x 1 1/4 in; 19.685 cm x 3.175 cm