World Library  
Flag as Inappropriate
Email this Article
 

Phot

A phot (ph) is a photometric unit of illuminance, or luminous flux through an area. It is not an SI unit, but rather is associated with the older centimetre gram second system of units. The name was coined by André Blondel in 1921.[1]

Metric equivalence:

1\ \mathrm{phot} = 1\ \frac{\mathrm{lumen}}{\mathrm{centimeter}^2} = 10,000\ \frac{\mathrm{lumens}}{\mathrm{meter}^2} = 10,000\ \mathrm{lux} = 10\ \mathrm{kilolux}

Metric dimensions:

illuminance = luminous intensity × solid angle / length2

See also

References

  1. ^ Parry Moon. "System of photometer concepts", in the Journal of the Optical Society of America, volume 32, number 6 (June 1942). – Page 355: "The lumen was proposed by Blondel in 1894 and is now universally accepted. The names, phot and stilb were likewise coined by Blondel (1921) and are in general use on the Continent."

External links

  • Knowledgedoor, LLC (2005). Library of Units and Constants: Illuminance Quantity. Retrieved 2006-07-21.
  • Illuminance Converter. Retrieved 2006-07-21.
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.