Patent ID: 6983636

Claim:
A method for assessing the liquid flow performance for dispensing liquid through a relatively small diameter dispensing orifice fluidly coupled to a communication passageway of a precision, low volume, liquid handling system, the method comprising: emitting an optical beam of a sensor assembly, from a position outboard from one side of the dispensing orifice, along an optical path extending substantially laterally across and downstream from the dispensing orifice of the liquid handling system prior to dispensing liquid from the dispensing orifice; continuously sensing the optical beam along the optical path, from a position outboard from an opposite side of the dispensing orifice; flowing the dispensing liquid through the communication passageway generally sufficient to eject at least a drop of dispensing liquid from the dispensing orifice, and across the optical path of the optical beam; and adjusting the sensitivity of the sensor assembly so that the drop of dispensed liquid from the dispensing orifice is more “visible” to the sensor assembly, wherein; detecting the drop indicates a flow condition of the dispensing fluid through the dispensing orifice; and wherein not detecting the drop indicates a non-flow condition of the dispensing fluid through the dispensing orifice.