Residual Intensity as a Function of Optical Depth along a Purely Absorbing Optical Path
τ
ν
r
ν
=
I
ν
/
I
ν0
= e
-
τ
ν
< 0.01
≈ 1 -
τ
ν
0.05
0.9512
0.10
0.9048
0.25
0.7788
0.50
0.6065
0.75
0.4724
1.00
0.3679
2.00
0.1353
5.00
0.0067
10.00
0.000454
¥
0