There are three types of calibration that a user can perform through the Opentrons App: deck calibration, pipette calibration, and labware calibration. These calibration processes save key positions and measurements to your OT-2 necessary for precise movement. In this article, you will learn about the data each calibration process provides your OT-2 and how your OT-2 uses that data.

What is deck calibration?

Deck calibration provides coordinates for key positions on the removable deck to the robot. In deck calibration, there are four data points that are saved:

  • a position flush with the deck on slot 5
  • engraved cross on slot 1
  • engraved cross on slot 3
  • engraved cross on slot 7


The first position saved, a position flush with the deck on slot 5, is known as the "z-offset." The z-offset tells your OT-2 how low the deck is and helps the OT-2 move pipettes up and down with precision relative to your labware. Your OT-2 uses the length of Opentrons tips in its calculations, so it is important to use Opentrons tips during deck calibration.

Engraved crosses on slots 1, 3, and 7

These three points give the robot the orientation of the deck and helps the robot move pipettes with precision the x and y axes. If these positions are not properly calibrated, you might see the robot fail to move to the center of wells in a single piece of labware as it iterates through the wells of a row or column.

What is pipette calibration?

Pipette calibration provides the length of the tip to your OT-2. This is the first calibration process completed after uploading a protocol. This information is used for labware calibration and precise movement during a run relative to labware.

Tip length

The data saved during pipette calibration is known as "tip length."  This tells the robot the length of the tip that is about to be used in the protocol. The data is saved per pipette model, so that each pipette model can save unique tip length data. 

What is labware calibration?

Labware calibration tells the robot where the center of each well is so that it can reliably move within each well as specified in a protocol. The data points saved are:

  • labware height
  • x & y offset

For more information, please refer to the following articles:

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