METHOD AND EQUIPMENT FOR DOSING SMALL AMOUNTS OF LIQUID QUANTITATIVELY

摘要

The invention relates to a method and equipment for quantitatively dosing small amounts of liquid, especially in clinical or other similar wet-chemical analyzers. The dosing employs a liquid space (1) the volume of which can be changed and which is connected to a dosing channel (5) so that, by increasing or decreasing the volume of the liquid space, a suction or an injection through the dosing channel is achieved. According to the invention the liquid space (1) is formed by flexible bellows (2) which are freely movable back and forth to provide the reversible deformations which change the volume of the liquid space. The movements are effected using an actuator (3) which is connected to the bellows (2) without transmissions containing sliding surfaces, the actuator comprising precisely repeatable positions and which is calibrated according to the invention by measuring the sizes of the dosages produced by the movements between the positions. The dosing is effected after that by selectively repeating said calibrated movements.