Patent ID: 6416294
Filing Date: 2002-07-09
Classification: B01J,B01L,C40B,F04B,G01F,G01N

Abstract:
A volume sensor-free microdosing device comprising:a pressure chamber which is at least partly delimited by a displacer; an actuating device for actuating the displacer, the volume of the pressure chamber being adapted to be changed by actuating the displacer; a media reservoir which is in fluid communication with the pressure chamber; an outlet opening which is in fluid communication with the pressure chamber; and a control means for driving the microdosing device, wherein; a first change of volume of the pressure chamber volume is effected per unit time by a movement of the displacer from a first position to a predetermined second position, the second position of the displacer defining a larger volume of the pressure chamber than the first position, thereby causing a fluid volume to be sucked into the pressure chamber; and in a second phase, a second volume change of the pressure chamber volume, which is greater than said first volume change, is effected per unit time by a movement of the displacer from a second position to the first position, thereby causing a defined fluid volume to be ejected from the outlet.