Thermo Scientific EASY-nLC 1200 Troubleshooting And Maintenance Manual page 168

7
Troubleshooting
Troubleshooting Tips
Weak or Absent Signal—Defective Precolumn
146 EASY-nLC 1200 Troubleshooting & Maintenance Guide
When compared to the Pump A graph for a normal run shown in
Figure 124 shows the reduced time for the precolumn equilibration and sample loading steps
when the precolumn is damaged and has lost a significant portion of its packing material.
The flow rate for the column equilibration and sample loading steps is higher (>15 µL/min)
and the duration is shorter because the precolumn is exerting less backpressure.
Note The specifications for the precolumns used to acquire the data in
Figure 119 are as follows:
• 2 cm length
• 100 µm ID
• 5 µm particle size
• C18
Figure 124. Typical pump A profile for a damaged precolumn
Column equilibration step
Figure 118 on page
Figure 118
The measured flow rate
is > 15 µL/min.
Sample loading step
Thermo Scientific
140,
and