Metrohm 790 Personal IC User Manual
Page 54
2.9 Putting into operation
790 Personal IC
45
3 Start system
• Make sure, that the aspirating tubing 6.1834.010 for the high-
pressure pump is immersed in the eluent.
• Select
Startup determination
from the
Control
menu in the sys-
tem window. The high-pressure pump and the peristaltic
pump are started, at the same time, a chromatogram window
is opened where the baseline is recorded continuously. The
suppressor module is automatically switched to the next
position every 20 min and conditioned in this way.
4 Set contact pressure for pump tubings
• Press contact pressure lever 41
41
41
41 on both tubing cartridges 40
40
40
40
upwards until regeneration and rinsing solution just start to be
drawn in.
• Then press contact pressure lever 41
41
41
41 upwards until it clicks
once more to obtain optimal contact pressure.
5 Check for leaks
• Check all capillaries and their connections between the high-
pressure pump and the detector block for escaping liquid. If
eluent escapes anywhere, the appropriate compression fit-
ting must be tightened further or changed.
6 Condition system
• Rinse the system with eluent until the desired stability of the
baseline is reached (normally 30…60 min; if the eluent is
changed, the establishment of the ion exchanger equilibrium
on the separating column can take longer). After this time the
suppressor module is sufficiently conditioned too.
• The instrument is now ready for sample determinations using
the selected system.
Pump tubings are consumable material with a lifetime, which depends
on the contact pressure. This is why the tubing cartridges should be
raised completely by loosening snap-action lever on the right-hand
side if the pump is to remain switched off for a considerable length of
time (the set contact pressure remains unchanged).