Liquid Level Detection
Hamilton offers both the traditional capacitive liquid level detection as well as pressure based liquid level detection. The software can use these functions to drive the pipette tip to just above the surface to do a jet dispense, or touch the surface for a wet dispense, or dive below sufficiently to aspirate liquid without drawing in any air.
Capacitive liquid level detection A weak electrical potential is created between the pipetting channel and the labware carrier. When using conductive tips (black) and an ionic liquid the capacitance of the circuit is measured. From this data the software can determine the height of the liquid surface and take appropriate action.
Pressure liquid level detection A pressure transducer inside the air displacement channel measures the pressure inside the barrel during pipetting. The data from this sensor changes as the tip approaches the liquid surface, touches the surface and drives below. This data can be used to control pipetting in real-time. Pressure level sensing is the only way to determine the level of non-ionic liquids.