Cap Pump G1367A shuts down after every sample

Hello Agilent community,

we are trying to use an Agilent 1290 Infinity Autosampler G7167B together with a binary cap pump G1376A .

After creating a sequence and starting it with any method the cap pump totally shuts down . The solvent flow falls to 0 and then starts again. We don´t want this to happen.

We need a constant solvent flow and pressure over the whole time the sequence is running. I tried to change settings inthe method configuration, but can´t find the solution.

Could it be a hardware set up issue ? Where do I have to look for a change? Any suggestions would help.

Thanks in advance


  • Sorry , i have to emphasize that the cap pump shuts down after every sample. Then it needs a Minute to set up the flow and pressure again. During this minute the autosampler loads the next sample and injects it, no matter what the flow/pressure looks like .

    We need a constant flow over the whole measuremnet of all samples. And only shut down at the end of the sequence.

  • Hello,

    You are mixing a capillary pump with an Analytical scale autosampler.  You didn't mention the flow rate but if you are using that pump in micro flow ranges, any pressure change will result in what you describe.  When the G7167B goes to make an injection, there is pathway switch [mainpass>bypass and then back to mainpass], which will cause a pressure differential.  That is why the G1376A behaves that way.  So, what you are struggling with can only be changed if you change the pump model.  I believe that pump can be changed from a micro to Normal mode which will allow you to operate it like a regular analytical pump up to 2ml/min but the EMPV and flow sensor will have to be bypassed.

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