Stone, J.
and Zimmerman, J.
(2001),
Index of Refraction of Air, Index of Refraction of Air, [online], http://emtoolbox.nist.gov/Wavelength/Documentation.asp
(Accessed October 31, 2024)
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Index of Refraction of Air
Published
Author(s)
,
Abstract
These Web pages are intended primarily as a computational tool that can be used to calculate the refractive index of air for a given wavelength of light and given atmospheric conditions (air temperature, pressure, and humidity). The calculations are performed using either the Ciddor equation or an updated version of the Edlen equation with a modification of the water vapor term so as to improve accuracy for shop-floor use at temperatures departing substantially from 20 degrees C. The text accompanying the calculations explains our modification of the Edlen water vapor term, provides a tutorial for users of the Web page, and reviews and discusses the relative merits of the two equations, the range of validity, and the estimated uncertainty of the calculations. In addition, the text gives a complete description of all calculations employed by the Web page so that others desiring to reproduce the calculation can do so. Finally, we propose a simplified formula that can be used for shop-floor computations of the refractive index when only a hand calculator is available.Citation
Index of Refraction of Air
Pub Type
Websites
Keywords
air refractive index, Ciddor equation, Edlen equation, index of refraction, interferometry
Citation
Issues
If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.
Created February 16, 2001, Updated June 2, 2021