Bio-Rad BioLogic Signal Import Module (SIM) - Manual (Page 38)

2.5.4 pH Monitor
The BioLogic DuoFlow pH monitor enables direct monitoring of pH conditions during a run. The pH monitor
is optional for all DuoFlow systems.
The pH monitor consists of the following:
• Flow cell: The PEEK flow cell has a swept volume of approximately 80 µl when the pH electrode is
inserted. The flow cell mounts to the BioLogic rack using an attached mounting bracket, which can
also be used to attach the UV detector and Conductivity monitor. The flow cell should be positioned
so that the flow path is angled upward to promote bubble clearance. Plumb the flow cell with the
inlet tube attached to the lower port and the outlet tube attached to the upper port. The inlet and
outlet ports are threaded for use with 1/16” (1.6 mm) OD tubing and 1/4-28 flat bottom fittings. The
pH monitor is designed for flow rates up to 80 ml/min and flow cell pressure less than 75 psi, and
therefore should be plumbed downstream of the backpressure regulator.
• pH electrode: The pH probe is a sealed Calomel type electrode consisting of a pH and a reference
electrode built into the same body. The sealed reference design eliminates the need to add
electrolyte solutions and minimizes reference dryout. The Calomel electrode is fully compatible with
buffers (such as Tris) that may not be compatible with the Ag/AgCl (silver/silver chloride) containing
electrodes.
• Signal Cable: To connect the pH probe to the BNC connector of a Signal Import Module or
Maximizer.
Figure 2-9. pH Monitor
The pH electrode and flow cell are described in detail in their separate documentation.
2.5.5 Other Detectors
Detectors other than those offered by Bio-Rad may be used when connected to the Signal Import Module
(SIM.) Refer to Section 2.9.6.
pH ELECTRODE
pH FLOW CELL
SIGNAL CABLE
DESCRIPTION OF BIOLOGIC DUOFLOW SYSTEM SYSTEM OVERVIEW
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