Bio-Rad BioLogic LP System - Manual (Page 18)

Figure 3 shows how the flow cell and the filters can be changed. To remove the flow cell, you will need to
remove the retaining clip from the bottom of the optics module and pull the luer connectors away from their
holders. Then loosen the thumbscrews and remove the flow cell. When inserting the replacement flow cell,
make sure the O-ring is securely placed on the flow cell. To change the filter, loosen the filter’s thumbscrew
and lift out and rotate the filter holder. The selected wavelength is indicated by the raised arrow on the bot-
tom of the case.
WARNING: To avoid exposure to UV radiation, turn off the UV lamp when changing filters and flow cells.
2.4 CONDUCTIVITY DETECTOR
The Conductivity Detector consists of a small, portable Conductivity Flow Cell and the control circuitry which
resides in the BioLogic LP Controller. This monitoring system provides a means to check equilibration con-
ditions and the formation of a salt gradient, for example, in ion-exchange chromatography and hydrophobic
interaction chromatography. This data helps in optimizing purification protocols and column cleaning proce-
dures.
Figure 4. Conductivity Flow Cell and Separate Holder
The Conductivity Flow Cell consists of the following:
• Flow cell with Inlet/Outlet ports: For connection of the tubing, using luer fittings. The flow cell allows
flow in either direction.
• Signal Cable: For connection to the back of the BioLogic LP Controller. Electrical power for the
Conductivity Flow Cell is drawn off the signal cable.
The flow cell can be plumbed immediately after the UV Optics Module’s flow cell or at any other point in the
flowpath. A separate holder for the Conductivity Flow Cell is mounted to the system rack. The swept vol-
ume in the cell is a nominal 2
µ
l.
Conductivity is measured in milli-Siemens (mS). For accurate measurement, the flow cell must be calibrat-
ed. Refer to Table 10.
Nine fixed Conductivity ranges, from 500 to 0.5 mS Full Scale (mSFS), are available. The user may choose
a “custom” range using the “Min/Max” function. Refer to Table 10.
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Description of Components