Effect of Filament Length on Performance of Drum Lenses,
Abstract
The peak beam candlepower of a lens-lamp combination depends upon the size and shape of the lamp filament. This relationship can be stated in terms of the variation of lens-to-lamp candlepower ratio with lamp filament length. Previous tests showed that the lens-to-lamp ratio increases with decreasing filament length. These previous tests were made with filaments having lengths from about 6 millimeters to 3.6 millimeters. In this report, measurements of lens to lamp ratios are presented for filaments having lengths of from 6 millimeters to 2.5 millimeters. These measurements are given for a 200 millimeter pressed glass drum lens, 300 millimeter pressed glass closed top drum lens, and a 375 millimeter cut-glass drum lens. (Modified author abstract)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 02, 1957
- Accession Number
- AD0787116
Entities
People
- C. F. Scharfenstein Jr.