ALS 7693 Autosampler tray gripper cannot release sample vial

Dear forum,

we are using an ALS 7693 Autosampler Tray to deliver samples to the injector turret.

The issue is, that the Sampler-Gripper sometimes goes in to error mode when releasing the samples back in to the Tray. The Gripper tries one more time and then places the sample into a default position in the back of the tray. My observation is, that the movement of the gripper jaws extends too much to the left and right. The gripper jaws collide with samples standing in adjacent positions (left and right of the gripper). In most of the cases, these samples move aside and allow the gripper to release his sample. However, from time to time and not reproducibly, the sample is not released and put to aforementionted default position. If this happens twice during a sequence, the whole sequence ist aborted.

Is there a way to calibrate or alter the range of the gripper jaw movement during sample release back to the tray? How can I affect travel of the Gripper Z-axis?  Would the "Aligning the Sample Tray" procedure found in the manual alleviate the problem? Is there a way to restore alignment parameters to factory setting, if the new alignment would worsen the situation?

Thanks in advance and have a great day


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  • Dear CMZainea,

    thank you for your quick response. Yeah, we are looking at the same manual and page - thanks for the link. However, only the "fault" light is on. The sampler tries to place the vial in its position twice and then places the vial in a fall-back position. To me, it looks like the jaws of the gripper are moving too close to the surrounding vials and collide with them in certain cases. A scratching noise is audible when the gripper jaws move outwards, much as if the gripper-drive is fighting against mechanical resistance. The crux is, that the sampler sometimes manages to push the adjacent vials aside and place the vial in its appropriate position. In other cases, the sampler goes into "fault" mode at the same vial position.

    Ideally, I would like to calibrate the width of the gripper jaw movement and/or the z-height of the whole gripper assembly during sample release. Curiously, the gripper jaws do not open as widely during sample-pick up and transfer to the turret.

    Now, I would readily initiate the realignment but I fear that I cannot revert back to factory settings if my alignment is completed but our problem got worse.

    Would I need to use the specific calibration vial for the alignment or is the alignment (as per page 247) done with our own vials or without any vial?

    Thank you very much for your help - much appreciated!

    Best regards and have a great day.


  • Hello  ,

    Thank you for your response.

    What is the pattern for the fault light? Is it solid, or is it blinking? And if it's blinking, how many times is it blinking? Depending on what the answer is, alignment may not be all that helpful.

  • Dear CMZainea,

    I have to say, I am impressed by how fast you respond to my questions. Awesome!

    The fault light flashes five times followed by a short pause and then it flashes five times again...and so on.

    Thank you for your help and looking forward to your suggestions


  • Hello  ,

    No worries at all :) I reach out whenever I have the time, and sometimes this is faster than others.

    Now, if you look in the same manual for the Sample Tray faults, the five flashes error code means a "Gripper error". It is possible that it is a mechanical issue and it cannot be addressed by aligning the tray.

    The alignment on page 247 does calibrate the gripper strength as well, as you can see it mentioned towards the bottom of page 247. But I would not think this is a guaranteed fix. To answer one of your previous questions, the alignment on page 247 does not require any special vials at all, you just press the alignment button and you let it do its thing. You would, of course, need to make sure that there is nothing in the way of the tray arm that would physically prevent its movement. 

    If you ever want to calibrate the tray (page 249), then you would require a calibration vial, but it's not the case here; that calibration addresses different symptoms.

    I am not sure how your local Agilent team addresses ALS/Tray issues; but since there are some concerns on your end on running the procedure, my recommendation would be to reach out to your local Agilent Team.

  • Dear CMZainea,

    thanks again for your response and help.

    So, alignment and calibration are the only two options that I have? If so, then I am going to try the alignment procedure. From what I understood, the calibration procedure is only heplful for sample placement into the injector turret. Would a new calibration of the sampler/turret combo have any impact on the gripper movement/gripper offset in regard of sample position?



  • Hello  ,

    Those the only options I would be familiar with and I can recommend.

    The calibration indeed seems to only address the sample transfer from tray to turret, and I don't imagine it has anything to do with the Gripper. Since you are getting a gripper error, I wouldn't be surprised if the calibration will fail because of it.

    Do let me know if the alignment fixes anything. And if it doesn't, as mentioned above, I would recommend to reach out to the local team (link in the previous message). Either that or maybe wait for someone else with a similar error to respond to this, and see what they might suggest.

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