Operating Principle - Thermo Scientific VC-D60 Operating Manual

3.2

Operating Principle

Refractive Index Detector (VC-D60)
Operating Manual
The detector is a deflection or Snell-type refractive index detector. It is
designed for analyses requiring the continuous monitoring of the
refractive index of a flowing liquid with respect to a reference.
Snell's Law states that a parallel light beam, when passing through a
dielectric interface separating two media of different refractive index at
an angle of incidence greater than zero, will be refracted at a function of
the magnitude of difference of the refractive indices of the two media.
incident beam
Figure 1: Snell's Law
Character Description
n index of refraction
i angle of incidence
r angle of refraction
v velocity of light in first medium
1
v velocity of light in second medium
3 • Device Overview
interface
refracted beam
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