| 摘要 |
PROBLEM TO BE SOLVED: To improve the dispensing accuracy by disposing several plunger return springs on the periphery of a plunger symmetrically, and providing the balance adjustment facilities between a plunger driving shaft and a fixed bar, and thereby correcting the unbalance in moving the plunger vertically. SOLUTION: A plunger driving shaft 11 is pushed down, and a plunger 14a, 14b are lowered against a plunger return spring 17a and 17b, so that a predetermined amount of a reagent aspirated in a tip 16a, 16b attached to the head of a cylinder 15a, 15b is dispensed. At this time, the inclination of a plunger fixed bar 13 based on the variation in frictional resistance between the plunger 14a, 14b and the cylinder 15a, 15b can be adjusted at a position in which a ball 21 is in contact with the driving shaft 11, using a screw of a balance adjustment facilities 18, and compensated by transmitting the depressing power produced from the driving shaft 11 to the balanced position of the bar 13. The inclination which remains to be compensated is absorbed into the spring 17a and 17b, and the displacement of each plunger 14a, 14b becomes entirely uniform, so that the uniformity of the amount of dispensation is realized and the accuracy in dispensing in small quantity is improved. |
