Patent ID: 6860137
Filing Date: 2005-03-01
Classification: B01F,G01N,Y10T

Abstract:
1. A method for obtaining an accurate mixing ratio of a liquid mixture in a liquid transfer device with a low pressure gradient function, comprising: providing a pump chamber having a plunger to provide suction and discharge operations; mixing at least two different liquids at a predetermined mixing ratio by changing a switching timing of switch valves, said at least two different liquids being held into the pump chamber by operation of the plunger and by switching the switch valves to thereby determine an actual mixing ratio of the at least two different liquids mixed together; calculating a mixing ratio error as a difference between said actual mixing ratio and said predetermined mixing ratio; storing said mixing ratio error in a memory; correcting the switching timing of the switch valves for the at least two different liquids based on said stored mixing ratio error in operating the plunger for a practical operation subsequently performed to thereby obtain the accurate mixing ratio of the at least two different liquids; and sequentially transferring said at least two different liquids as the practical operation by opening and closing the switch valves for the liquids, said switching timing of the switch valves being corrected for subsequent transfer of the at least two different liquids.