Prismatic Section: Difference between revisions
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{{languages|Prismatic Section}} | {{languages|Prismatic Section}} | ||
[[Category:2.2 Optical Apparatus] | [[Category:2.2 Optical Apparatus]] | ||
[[Category:Alphabetical Index]] | [[Category:Alphabetical Index]] | ||
[[Category:IALA Dictionary 1970-89 Edition]] | [[Category:IALA Dictionary 1970-89 Edition]] | ||
Revision as of 00:05, 25 February 2009
2-2-020
1. Cross-section of a prism by a plane normal to the refracting edge. The section is bounded by straight lines (usually three).
2. In lighthouse practice, the term is also used for a cross-section of a transparent optical element bounded by three straight or slightly curved sides, approximating to a triangle, but of such shape that incident parallel rays of a particular wavelength are focussed after refraction or reflection (or both) by the section.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
