Standard: ASME - ANSI Y10.18


This standard is available for individual purchase.

or unlock this standard with a subscription to IHS Standards Expert

IHS Standards Expert subscription, simplifies and expedites the process for finding and managing standards by giving you access to standards from over 370 standards developing organizations (SDOs).

  • Maximize product development and R&D with direct access to over 1.6 million standards
  • Discover new markets: Identify unmet needs and discover next-generation technologies
  • Improve quality by leveraging consistent standards to meet customer and market requirements
  • Minimize risk: Mitigate liability and better understand compliance regulations
  • Boost efficiency: Speed up research, capture and reuse expertise
For additional product information, visit the IHS Standards Expert page.

For more information or a custom quote, visit the IHS Contact Us page for regional contact information.

CLOSE cooperation of Committees of the International Commission on Illumination, the International Organization for Standardization, the International Electrotechnical Commission, and the SUN Commission of the International Union of Pure and Applied Physics is resulting in the development of a set of terms and symbols that should, and hopefully will, receive acceptance throughout the entire world. The symbols in the USA Standard Letter Symbols for Illuminating Engineering are consistent with the international agreements that have been reached to date.

The outstanding features of the symbols in this Standard are (1) the use of the same set of symbols for radiometric and photometric quantities with the proviso that when there is need to differentiate these quantities subscripts e and v, respectively, will be used, and (2) the use of a subscript λ to designate a spectral concentration and λ in parenthesis to designate a function of wavelength (the adjective spectral is used in English to indicate both of these meanings, but in French, the adjective spectrique is substituted for spectral for the first meaning when there is a need to avoid ambiguity).

This standard was prepared by Subcommittee of Sectional Committee Y10. Following its approval by the Sectional Committee and the sponsor, it was approved by the USA Standards Institute on February 2, 1967.

Organization: ASME International
Document Number: ansi y10.18
Publish Date: 1967-01-01
Page Count: 11
Change Type: REAF
Available Languages: EN
DOD Adopted: NO
ANSI Approved: YES
Most Recent Revision: YES
Current Version: NO
Status: Inactive

Document History

Document # Change Type Update Date Revision Status
ANSI Y10.18 Change Type: REAF Revision: 67 Status: INAC
ANSI Y10.18 Change Type: Revision: 67 Status: INAC