We have a sample that has an atypically high volume in a deep well nunc type plate and we keep getting this error which i’ve never encountered before. I’m pretty confident we’ve processed this volume before without error, so i’m confused why this is happening now.
What does this “unexpected cLLD error” mean, and what can i do to get around it, as the error recovery options don’t offer “bottom” which is normally what we would do.
Hi @cdm ,
Unexpected Liquid Level error means the channel has detected a change in capacitance before it reaches the location that detection begins. As an example: when an aspiration using cLLD begins, the channel will move to the XY coordinate while the Z is at travel height. Afterwards, it will move quickly to a Z height that is defined by the container definition as the Liquid Seeking Height. Upon reaching this height, the Z speed will slow down as it tracks to find the liquid level. Your channel is saying that it “found” liquid during the initial fast Z movement down.
Typically, this happens because a labware definition is set such that the Liquid Seeking Height is within the container which means liquid could potentially be filled to a point that the channel is already submerged before liquid sensing begins. Which will throw this error.
I would suggest running a test method where your tube is either empty or very low and observe what height your channel changes from the fast movement in Z to the slower searching speed. If this transition is within your container, then you will need to increase the value below in the container definition to ensure the liquid seeking is always starting above the well.
If this is not the case, and the search height is properly set above the well, then it could be possible that your channel needs to be serviced.
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Thank you this is really helpful - i’ll give it a try