Patent ID: 8689615

Claim:
A method of determining the presence or absence of bubbles within a pipe in a dispensing apparatus for performing a dispense, comprising the steps of: a) detecting pressure within the pipe, before performing the dispense; and b) determining the presence or absence of bubbles within the pipe based on the detection result of the pressure within the pipe, wherein step b) includes: calculating a slope of each of a plurality of pressure waveform portions obtained by dividing a waveform of the detected pressure such that the plurality of pressure waveform portions correspond to a plurality of segments along the time axis; determining whether or not the calculated slope of each of the plurality of pressure waveform portions is outside a predetermined range; and determining the presence or absence of bubbles within the pipe, based on the number of segments in which the respective calculated slopes of the plurality of pressure waveform portions are determined to be outside the predetermined range.