An automated micro-valve assembly injects a fixed fluid volume fluid into a destination stream. The fluid to be injected (inject fluid) is conducted into a chamber. Flow of inject fluid out of the chamber is prevented by sealing the ends of the chamber using valves or by application of pressure. A fixed...http://www.google.com.tw/patents/US5487313?utm_source=gb-gplus-share專利 US5487313 - Fluid-lock fixed-volume injector
