General Electric "Purple X" black-light lamp
date: label: date made
content: ca 1978
name: label: maker
content: General Electric Company
notes: label: Description (Brief)
content: General Electric "Purple X" black-light lamp. Characteristics: aluminum medium-screw base with glass insulator. Tungsten CC-9 filament with molybdenum supports. Tipless A-21 glass envelope with purple-colored glass. Lamp appears in the GE catalogs from 1955 thru 1979, and was for intermittent burning only to supply ultraviolet radiation for energizing fluorescent materials. Life rating: 50 hours.
label: Description (Brief)
content: A former GE engineer wrote: "The "Purple-X" lamp is a good example of "square peg, round hole." It was a hard-to-use lamp as it got very hot and had to be operated on an on/off cycle. The glass of the bulb was expensive because it wasn't a coating, but rather what was called "Woods glass" or "pot glass." But, that type of glass was difficult to process into bulbs. ... The purpose of the Purple-X was to produce just a bit of near UV or "black light" for school experiments (rocks and mineral identification) or commercial laboratory and inspection work. It was a specialty product, but important enough that GE published a UV Application Bulletin with sketches and pictures of black light applications. [A copy is in the file.] ... “So, the Purple-X was hot, inefficient, expensive and didn't generate much UV; but it was an incandescent bulb that people understood how to use and it could be screwed into a standard socket. Fluorescent black light lamps were a much better source of UV."
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Paul Henling, thru Brian and Geri Henling
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 2012.0232.01
label: accession number
content: 2012.0232
label: catalog number
content: 2012.0232.01
objectType: label: Object Name
content: incandescent lamp
physicalDescription: label: Measurements
content: overall: 5 in x 2 5/8 in; 12.7 cm x 6.6675 cm