Thermo Scientific Accela UV/Vis Plus, Hardware Manual

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1
Introduction
LightPipe Flow Cells
Thermo Scientific Accela UV/Vis Detector Hardware Manual 3
From the grating, the light travels to a fiber optic beamsplitter, where a portion of the light is
redirected to a reference photodiode. The signal from the reference photodiode compensates
for changes in lamp intensity and helps maintain consistent performance as the lamp
performance varies. From the beamsplitter, most of the light passes through a lens and then on
through the flow cell and onto the sample photodiode. The analog PC board converts the
intensity counts from the photons falling on the sample photodiode into data that the data
system can process.
Light-emitting diodes (LEDs) on the front of the module provide information about power,
communications, run, and lamp status. See
“Status LEDs” on page 7 .
LightPipe Flow Cells
The UV/Vis detector is available with a 10 mm (2 μL volume) or 50 mm (10 μL volume)
LightPipe™ flow cell.
The mobile phase enters the LightPipe flow cell through the inlet port and exits through the
outlet port. Directing the flow from the bottom to the top of the flow cell reduces the
development of air bubbles.
On the 10 mm LightPipe flow cell, the inlet port is on the bottom and the outlet port is on
the side (
Figure 3 ).
Figure 3. 10 mm LightPipe flow cell schematic
On the 50 mm LightPipe flow cell, the inlet port is on the bottom and the outlet port is on
the top (
Figure 4 ).
Note A standard analytical (10 mm) flow cell is available as an option. For information
about installing a standard analytical flow cell, see “Installing the Standard Analytical Flow
Cell” on page 21 .
Outlet port Inlet port
Alignment slot (top)