Agilent InfinityLab LC Series RID User Manual
16
1
Introduction to the Refractive Index Detector
How the Detector Operates
How the Detector Operates
Refractive
index
When a beam of light passes from one medium into another, the wave velocity
and direction changes. The change in direction is called refraction. The
relationship between the angle of incidence and the angle of refraction is
expressed in Snell's Law of refraction.
Where:
•
n = Refractive index of medium 1 relative to medium 2
•
n
2
= Refractive index of medium 2
•
n
1
= Refractive index of medium 1
•
α
1
= angle of incident light in medium 1
•
α
2
= angle of refraction in medium 2
Figure 4
Light Refraction
Medium 1
Medium 2
