
50-6 Optical
the concentration in the eluted solvent relative to the pure solvent. A stable folded Jamin interferometer
fo
r
re
fractive
in
dex
me
asurements
is de
scribed
by Mo
osmller
an
d
Ar
nott
[7
]
. Li
quid
re
fractive
in
dex
me
asurements
u
sing
a M
ichelson
i
nterferometer
a
re
d
escribed
b
y
R
icherzhagen
[
8]
.
50.3.2 Deviation Methods
Lateral and angular deviation methods make use of Snell’s law (Equation 50.2). e incident beam is
us
ually
i
n
a
ir,
o
f
r
efractive
i
ndex
n
air
.
La
teral
de
viation
l oc
curs
fo
r
a be
am
of li
ght
tr
ansmitted
th
rough
a pa
rallel-sided
sa
mple
of th
ickness
L (
see
F
igure
5
0
.5). I
f
t
he
i
ncident
a
ngle
i
s
θ
air
, Snell’s law (Equation 50.2