A simple laser refractometer based on the detection of the critical angle for liquids is presented. The calibrated refractometer presents up to 0.000 11 of uncertainty when the refractive index is in the range between 1.300 00 and 1.340 00. The experimental setup is easy to construct and the material needed is available at most optics laboratories. The calibration method is simple and can be used in other devices. The refractive index measurements in aqueous solutions of sodium chloride were carried out to test the device and a linear dependence between the refractive index and the salt concentration was found.

Topics
Phase transitions, Measuring instruments, Fundamental constants, Photoresistors, Wheatstone bridge circuit, Geometrical optics, Optical devices, Optical properties, Refractometers, Lasers
1.
D.
 
Shomaker
,
C.
 
Garland
, and
J.
 
Nibler
,
Experiments in Physical Chemistry
, 5th ed. (
McGraw-Hill
,
New York
,
1989
).
Google Scholar
 
2.
A. A.
 
Zaidi
,
Y.
 
Makdisi
,
K. S.
 
Bhatia
, and
I.
 
Abutahum
,
Rev. Sci. Instrum.
https://doi.org/10.1063/1.1141028
 
60
,
803
(
1989
).
Google Scholar
Crossref
Search ADS
 
3.
A. A.
 
Zaidi
,
Rev. Sci. Instrum.
 
59
,
1153
(
1989
).
Google Scholar
Crossref
Search ADS
 
4.
S.
 
Sainov
,
Y.
 
Sarov
, and
S.
 
Kurtev
,
Rev. Sci. Instrum.
 
13
,
2327
(
2003
).
Google Scholar
 
5.
Annual Reference Catalog for Optics, Science and Education
(
Edmund Scentific
,
Barrington, NJ
,
1993
).
6.
E.
 
Hecht
 and
A.
 
Zajac
,
Optica, Versión Española
(
Fondo Educativo Interamericano
,
S. A., New York
,
1977
).
Google Scholar
 
7.
SIGMA
,
Reactivos y Productos Químicos
(
SIGMA
,
México
,
2001
).
8.
I.
 
Thormählen
,
J.
 
Straub
, and
U.
 
Grigull
,
J. Phys. Chem. Ref. Data
 
4
,
933
(
1985
).
Google Scholar
 
© 2006 American Institute of Physics.
2006
American Institute of Physics
You do not currently have access to this content.