Metrohm 861 Advanced Compact IC - Manual (Page 82)

4 Notes - Maintenance - Faults
861 Advanced Compact IC / Instructions for Use 8.861.1033
72
• Unscrew column 73 from column connection capillary 26 or
the precolumn.
2 Rinse with eluent
• Place beaker beneath the column connection capillary 26.
• Rinse IC system with eluent used for the separating column
(flow rate 1 mL/min) for approx. 15 min.
3 Connect new column to injection valve
• Remove end caps from column 73.
• Screw inlet end of separating column 73 (note flow direction)
to column connection capillary 26 or to the precolumn (see
Section 2.7.4/2.7.5).
4 Rinse column
• Place beaker beneath the column outlet.
• Set flow rate for new separating column.
• Switch on high-pressure pump and rinse column with eluent
for approx. 10 min, then switch off pump.
5 Connect column to detector block
• Screw outlet end of separating column 73 to inlet capillary 44
or suppressor inlet capillary 82.
4.2.6 Maintenance work at the pump head
In many cases, an unstable baseline (pulsation, flow fluctuations) can
be traced to contaminated valves or faulty, leaky piston seals at the
high-pressure pump. For cleaning contaminated valves and/or re-
placement of wear parts such as pistons, piston seals and valves, pro-
ceed as follows:
1 Detach pump head
• Switch off pump drive of the IC Pump.
• Disconnect aspirating tubing 63 from aspirating capillary 38
at the pump head 40 (see Figure 3 / Figure 4 / Figure 5).
• Unscrew connection capillary 39 from the pump head 40.
• Remove the pump head 40 by slackening the 4 securing
screws on the front of the pump head with the aid of the Allen
key 6.2621.030 from the pump housing. The main piston is
located at the left (when viewed from the front) and the auxil-
iary piston is located at the right.
2 Disassemble pump head
• Strip down pump head 40 in accordance with Figure 19. Main
and auxiliary pistons are identical with the following excep-
tions:
-
The spring 93 of the auxiliary piston (right piston) is more
powerful (longer) than that of the main piston (left piston).
-
Inlet and outlet valve are not present in the secondary cy-
linder.