Bio-Rad BioLogic Signal Import Module (SIM) - Manual (Page 36)

2.5.2 Conductivity Monitor
The Conductivity monitor, included with all DuoFlow systems, measures fluid conductivity to track the
accuracy of a salt gradient. This data is useful for optimizing purification protocols and column cleaning
procedures. Conductivity monitor sensitivity ranges from 0 to 500 mS/cm. The Conductivity monitor consists
of the following:
• Flow cell with Inlet/Outlet ports: To connect the tubing, use 1/4-28 flat bottom fittings. The flow cell
allows flow in either direction. The flow cell can be plumbed immediately after the UV flow cell or at any
other point in the flowpath. It is designed to fit into a receptacle on the UV detector (see Figure 2-7).
The volume in the cell is a nominal 6
µl.
• Signal cable: To connect to the back of the Workstation. Electrical power for the Conductivity monitor is
drawn from the signal cable. If a Maximizer is in use, connect to its COND port.
Figure 2-7. Conductivity Monitor
The Conductivity monitor can be calibrated by either entering the cell constant or by calibrating the cell
against a known standard. The Conductivity Flow Cell Constant Calibration feature is found under the
Utilities drop-down menu. The cell constant can be found on the tag attached to the cable.
The Conductivity sensitivity range for the chart recorder is set in the system software Manual and Run
screens. When setting the range, choose one that will accommodate the maximum conductivity expected
during the chromatography run. Keep in mind that although the chart recorder range can be manipulated
during a chromatography run, the data will be stored unattenuated, allowing for re-scaling at a later time.
2.5.3 QuadTec UV/VIS Detector
The BioLogic QuadTec UV/Vis detector enables four wavelengths to be monitored simultaneously and
displayed on the DuoFlow Controller. The QuadTec detector has a wavelength range of 190-370 nm using
the deuterium lamp and 370-740 nm with the halogen lamp. The deuterium lamp is standard and is required
for the detection of peptides, proteins, and nucleic acids. Both lamps are pre-aligned, calibrated, and user-
serviceable.
Wavelengths are selected through the use of a moveable grating monochromator with an accuracy of +/- 1
nm in 1 nm steps. When using the deuterium lamp for the monitoring of wavelengths >380 nm, an automatic
cutoff filter is activated. Because very little light of wavelengths greater than 400 nm is emitted from a
deuterium lamp, the halogen lamp is required for routine detection above 380 nm.
The QuadTec includes the following:
• 3mm Peek Flow Cell (1 µl flow cell volume, 4 µl including flow cell inlet and outlet tubes)
• 10-32 Fingertight fittings (quantity 4)
CONDUCTIVITY MONITOR
FLOW CELL
SIGNAL CABLE TO
CONDUCTIVITY FLOW CELL CONNECTOR
ON REAR OF WORKSTATION
DESCRIPTION OF BIOLOGIC DUOFLOW SYSTEM SYSTEM OVERVIEW
2-23