Thermo Scientific Surveyor UV Plus, Hardware Manual

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1
Introduction
LightPipe Flow Cell
Thermo Scientific Surveyor UV/Vis Plus 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 .
You can order the UV/Vis detector with one of these flow cell options:
• Standard analytical flow cell with a 10 mm path length
• LightPipe™ flow cell with a 50 mm path length
You can order other flow cells as options for the detector. See Table 5 .
LightPipe Flow Cell
The internal bore of the LightPipe flow cell is 50 mm long and has a volume of 10 μL. The
5 cm optical path length produces a signal five times that of a conventional 1 cm flow cell,
while the low internal volume of 10 μL minimizes band broadening. A special low refractive
index coating of the internal bore ensures a high optical throughput and minimizes
short-term noise.
Mobile phase enters the LightPipe flow cell through a port in the bottom of the flow cell and
exits through a port in the top of the flow cell. See
Figure 3 . Directing the flow from the
bottom to the top of the flow cell reduces the development of air bubbles.
Figure 3. 50 mm LightPipe flow cell schematic
50 mm flow path Inlet port
Alignment slot (top) Outlet port