Theory Of Operation; Optical System - Thermo Scientific Surveyor RI Plus Hardware Manual

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Introduction

Theory of Operation

Theory of Operation

Optical System

6 Surveyor RI Plus Detector Hardware Manual
The Surveyor RI Plus Detector consists of a high-quality optical system and a flowcell. This
section contains the following topics:
• Optical System
• Flowcell
The optical design of the Surveyor RI Plus Detector is based on Snell's Law of Refraction,
which uses a prism flowcell. The detector has a flowcell with two compartments that (the
sample and reference) form a pair of liquid prisms.
A beam of light is directed through the flowcell. As the light passes through the reference and
sample compartments of the flowcell, it is deflected. This deflection is proportional to the
difference in the refractive indices of the reference and sample solvents. The detector converts
the deflection detected by a photodiode into an output signal that it sends to the data system.
ChromQuest converts the output signal from the detector and displays the result in the
dimensionless units of RI.
the components involved in this process.
Figure 5. Deflection type refractive index detector
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Table 3. Deflection type refractive index detector
Item No. Description
1 Light
2 Sample compartment
3 Reference compartment
4 Light beam at the time of n
5 Light beam at the time of n
6 Displacement
7 Photodiode
n Refractive index of liquid in sample compartment
s
n Refractive index of liquid in reference compartment
r
Figure 5 contains a representation of this process and
2 4
n
s
n
r
3 5
> n
s r
= n
s r
Table 3
6 7
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