Tungsten lamp

Description

A type of incandescent lamp. Tungsten lamps were patented in 1913 by William Coolidge. The long-burning bulbs have a tungsten filament inside a sealed glass bulb filled with argon and nitrogen. Tungsten halogen lamps have a tungsten filament inside a quartz bulb filled with halogen. The halogen filled bulbs burn brighter and longer than tungsten lamps filled with inert gases. Non-halogen filled tungsten lamps are the most frequently used incandescent lamp. Their color temperature is warmer than fluorescent. They emit little UV light but produce large amounts of IR. They are used indoors and outdoors for many types of lighting. In museums, tungsten lamps, with IR filters, are often used for photographing art objects because of their high color rendering index.

Synonyms and Related Terms

tungsten filament bulb; tungsten incandescent bulb

Other Properties

Color temperature ~ 2500 K Color rendering index = 92 UV emissions can vary from 12-80 microwatts per lumen depending on type of bulb, power and filament temperature.

Sources Checked for Data in Record

• Marjorie Shelley, The Care and Handling of Art Objects, The Metropolitan Museum, New York, 1987

• Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996

• Book and Paper Group, Paper Conservation Catalog, AIC, 1984, 1989

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998