Patent ID: 7878765
Filing Date: 2011-02-01
Classification: F04B

Abstract:
1. A method for controlling fluid pressure in a multiple stage pump comprising: accessing a baseline pressure profile for a known good dispense cycle; operating a feed pump, a dispense pump and a set of valves to perform a new dispense cycle including a fill segment and a dispense segment; continually taking pressure measurements during the dispense cycle of fluid in a dispense chamber using a pressure sensor disposed to measure pressure in the dispense chamber; creating a first operating profile from the pressure measurements taken during the new dispense cycle; during one or more of the fill segment or the dispense segment of the new dispense cycle, comparing each of one or more values associated with the first operating profile with a corresponding value associated with the baseline profile to determine if each of the one or more values associated with the first operating profile is within a tolerance of the corresponding value associated with the baseline profile; and during one or more of the fill segment or the dispense segment, if the one or more values associated with the first operating profile is not within tolerances, generating an alarm; wherein operating the feed pump, dispense pump and set of valves to perform the fill segment comprises: