Hi we have a problem with our LDC analytical constametric 3200 pump: when injecting the sample (after some minutes) we experience a big pressure drop waving up and down for a while. Did someone have the same problem? What can it be?
Further the UV signal registered by the detector goes upward or downward constantly (and linearly) for a while untill settling on another value different from zero.

Thanks
Dario

When you say pressure drop, are you comparing the pressure when the injector is in the load or injector loop bypass position to the pressure when the injector is in the run position where flow is going through the injector loop? Or do you mean the pressure is at one value when it is in the run position, you load your sample, and when you go back to the run position the pressure is lower that it was before the sample was loaded?

Hello Dario,
I would guess you have air in the system.
What is the condition of the seals?
Do you see leaks anywhere?
What`s the pressure range?
Is the solvent filter clean?
bill

Hi
thanks for the help!
we noticed that a pressure waving (read on the display of the pump) occurs some minutes after the injection of the sample. We don't know if the two event are correlated, but we can't experience any pressure waving simply eluating the solvent (but we are trying...)
The pressure goes up and down between about 700/800-1250 psi (sometimes less), at 1ml/min.
How may i verify leaks, seal worn, and clearness of the filter?
Unfortunatly we lost the manual of the HPLC so we don't know much about it.
It is an old "LDC analytical constametric 3200" with an UV detector "LDC analytical spectromonitor 3200".
Has someone this manual got?