| 摘要 |
A method and apparatus for dispensing small volumes of fluid using a pneumatic control valve connected to the intake port of a pump having a chamber of variable volume, connecting the outlet port of the pump to the inlet port of a high speed flow control valve and a long, small diameter nozzle to the outlet port of the flow control valve, to aspirate a fluid to be dispensed into a long, small diameter nozzle by closing the pneumatic control valve, opening the flow control valve and partially expanding the volume of the pump chamber, then closing the flow control valve and further expanding the volume of the pump chamber to increase the gaseous volume within the pump chamber, pressurizing the gas within the pump chamber by closing the pneumatic control valve and reducing the volume of the pump chamber, finally dispensing a measured amount of fluid by briefly opening the flow control valve for a measured time to allow controlled amounts of fluid to be dispensed through the nozzle.
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