Bio-Rad BioLogic Signal Import Module (SIM) - Manual (Page 62)

The following procedure describes ferrule installation.
1. Slide the nut, stainless steel compression ring and the ferrule, in that order, onto the tubing as
shown at left. The flattened end of the ring should face the nut. The tapered end of the ferrule
should face the ring.
2. Allow tubing to extend slightly beyond the end of the ferrule.
3. Place the fitting into the green fittings tightener. Do not allow the tubing to slip out of the ferrule.
4. Insert the tubing and fitting into the fittings tool to tighten to seat the ferrule onto the tubing, do not
overtighten.
2.9.5 Backpressure Regulator
The 40 psi backpressure regulator is used with flow rates below 10 ml/min. Plumb the backpressure
regulator following the direction of the arrow.
The Backpressure Regulator helps eliminate bubble formation within the detector. As a solution is pumped
through a column, the column exerts a backpressure that serves to keep any air bubbles in solution.
Solution exiting the column returns to atmospheric pressure and air bubbles may form. As the bubbles pass
through, or lodge in the detector flow cell they may cause artifacts on the baseline chromatogram that
appear as spikes. This “outgassing” may be minimized by thoroughly degassing buffers and by placing a
backpressure regulator after the Conductivity monitor. The backpressure from the regulator helps to keep
the bubbles in solution.
When using low pressure columns such as an Econo-Pac® cartridge, plumb the 40 psi backpressure
regulator between the Workstation pump outlet and the mixer. This aids in seating the check valves,
preventing permanent damage to the cartridge or column.
Figure 2-28. Backpressure Regulator
DESCRIPTION OF SYSTEM COMPONENTS SYSTEM OVERVIEW
2-49