A method of filtering out pressure noise generated by one or more piston pumps, where each pump is connected to a common downstream piping system, and where the discharge pressure is measured by a pressure sensitive gauge, wherein the instantaneous angular position(s) of the pump(s)' crankshaft or actuating...http://www.google.com.au/patents/US7830749?utm_source=gb-gplus-sharePatent US7830749 - Method of filtering pump noise
