Sample Pressure trace - expected patterns?

<p> I was wondering if there is a typical plot pattern you look for in the "Sample Pressure" trace. Much like you can diagnose binary pump problems by looking at the different traces for the primary and accumulator for A and B, I'd like to know if the sample pressure trace can hint at any potential problems.</p><p>Do the traces change shape based on type of injection? (partial loop vs full loop)</p><p>How about for the different injection volumes?</p><p>I don't have any specific problem, but was just curious to hear any thoughts on predicting when an UPLC system might be headed downhill.</p><p>Thanks for any input!</p><p>Laura</p>


  • Hi Laura

    Attached you will find examples of typical pressure traces for the 3 different injection modes, full loop, partial loop and PLUNO. So yes they will look different for the different injection modes. In my opinion the most important thing to look for is that they are consistent for the same type of injection, over a full sample set for example. If the pressure does not go up during the weak and strong wash it might indicate air in the syringes or no wash solvent at all.

    best regards


  • LNE33

    Yes, Rune, this is just what I was looking for.

    Does the pressure transducer in the fluidics drawer provide the readbacks for the sample pressure trace? It must be a different component than what provides the overall system pressure reading.

    Thank you,


  • rune

    Hi Laura

    Yes you are correct. It is the pressure transducer in the fluidics drawer that measures the pressure in the sample manager.

    Best regards