Kone Oy

Fluilogic Systems Oy

Pertti Tuominen

Niilo Kaartinen

Keijo Makela

Unto Okkonen

Pertti Nuopponen

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, the volume of which can be changed and which is connected to a dosing channel so that, by increasing or decreasing the volume of the liquid space, a suction or an injection through the dosing channel is achieved. The liquid space is formed by flexible bellows 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 which is connected to the bellows without transmissions containing sliding surfaces. The actuator comprises precisely repeatable positions and 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 repealing the calibrated movements. The actuator can be formed by a stepper motor, and a cam shaft rotated by the stepper motor propelling the bellows back and forth. The nonlinear interdependent relationship between the rotation of the shaft and the change in the volume of the liquid space makes possible a wide range of calibrated dosage sizes.

Method and equipment for dosing small amounts of liquid quantitatively

A procedure for implementing the liquid selection of analyzer liquid dispension, includes the steps of selecting a liquid vessel from among a plurality of such vessels, and taking liquid into the dispensing system for further treatment. The liquid path from the liquid vessel that has been selected is so connected to the dispensing unit that (i) the sealing surfaces constituting the connection do not substantially slide against one another and that (ii) sealing at the connection is accomplished by means of elastic deformation of at least one of the bodies being coupled.

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Espoo, Finland

Pertti Tuominen