Skip to main content
U.S. flag

An official website of the United States government

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.

Laser Refractometer as a Transfer Standard of the Pascal



Patrick Egan, Jack A. Stone Jr., Jacob Edmond Ricker, Jay H. Hendricks


We have developed a new low pressure sensor which is based on the measurement of (nitrogen) gas refractivity inside a Fabry-Perot (FP) cavity. We compare pressure determinations via this laser refractometer to that of well-established ultrasonic manometers throughout the range 100} Pa to 100,000 Pa. The refractometer demonstrates 10^-6} precision for p > 50 kPa;---as good or better than the manometer---we argue that a laser refractometer represents a state-of-the-art transfer standard of the pascal. We also claim the refractometer has an accuracy of U(p_FP) = [ (16 mPa)^2 + (11.9 x 10^-6} * p)^2]^1⁄2, as realized through the properties of nitrogen gas.
Proceedings Title
CPEM 2016 Digest
Conference Dates
July 10-15, 2016
Conference Location
Ottawa, CA
Conference Title
Conference on Precision Electromagnetic Measurements (CPEM) 2016


Egan, P. , Stone Jr., J. , Ricker, J. and Hendricks, J. (2016), Laser Refractometer as a Transfer Standard of the Pascal, CPEM 2016 Digest, Ottawa, CA, [online], (Accessed July 22, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created July 9, 2016, Updated April 1, 2022