Calibrating means for a microdispenser

摘要

Calibrating means for a microdispenser of the type wherein a plunger is operable to automatically draw a fixed volume of fluid into, and expel the liquid from, a precision capillary tube. The calibrating means includes a graduation marking on the capillary tube indicating the precise, predetermined quantity of fluid to be drawn into the tube. Calibration is effected by varying the degree of engagement of the microdispenser end cap with the microdispenser barrel, which effects corresponding longitudinal movement of the plunger with respect to the capillary tube until the outer terminal thereof is aligned with the graduation marking on the capillary tube. Friction means are provided for preventing accidental movement of the end cap after the calibration adjustment has been made.