Metrohm 752 Pump Unit - Manual (Page 20)

4.1 Insufficient or non-existing flow rate
752 Pump Unit
17
4 Troubleshooting
4.1 Insufficient or non-existing flow rate
If the 752 Pump Unit is supplying insufficient liquid or no liquid at all
then this can be remedied by proceeding as follows:
1 Set contact pressure correctly
• Press contact pressure lever 55 on the tubing cartridge down
as far as it will go.
• Press contact pressure lever 55 upwards until the solution just
starts to be drawn in. Then press contact pressure lever up-
wards until it clicks once more to obtain optimal contact pres-
sure.
2 Exchange the pump tubing
• If the delivery performance is still not satisfactory then the
pump tubing must be exchanged (see section 4.3).
• After the pump tubing has been exchanged press contact
pressure level 55 on the tubing cartridge down as far as it will
go.
• Press contact pressure level 55 upwards until the solution just
starts to be drawn in. Then press contact pressure lever up-
wards until it clicks once more to obtain optimal contact pres-
sure.
3 Check the connections
• If the delivery performance is still not satisfactory even with
the new pump tubing then the connections must be checked.
• Loosen the first connection after the tubing cartridge in the
supply direction. If liquid is still flowing here then retighten the
connection and release the following connection and so on.
• Replace the connection at which liquid transport ceases or
exchange the connection pieces.
• If liquid transport ceases after the Filter unit PEEK, replace
filter 21 21 (6.2824.110; see Fig. 6).
• If liquid transport ceases after the suppressor module then
this should be exchanged.
4.2 Leaking of tubing nipples
If liquid is leaking from the tubing nipples then these must be tightened
up further. If the fault cannot be cured in this way then the tubing nip-
ples must be replaced.