Thermo Scientific Accela Pump, Hardware Manual

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1
Introduction
Functional Description
4 Accela RI Detector Hardware Manual Thermo Scientific
Figure 4. Movement of the image on the photodiode
The electrical signals emitted respectively from diodes A and B change in proportion to the
movement of the image. You can obtain a signal corresponding to the difference in refractive
index from the difference between the two signal outputs.
Flowcell
The flowcell consists of a reference compartment and a sample compartment. During normal
operation, the reference compartment is shut off from the solvent path. You can replace the
solvent in the reference compartment by using the purge control feature provided in the data
system.
Figure 5 on page 5 is a diagram of the solvent path through the flowcell, depending on how
you have set up purge control:
• When the Purge Control is On , solvent flows through both the sample and the reference
compartments of the flowcell.
• When the Purge Control is Off , the reference compartment of the flowcell is shut off
from the solvent path.
Image
Diode B Diode A
Image
Diode B Diode A
a. No difference in the
refractive index
b. Some difference in the
refractive index