Abstract: A sampling system, favorably applicable to an automatic chemical analyzer, is provided for sampling by sucking and discharging liquid, such as specimens and reagents. The sampling system comprises a pump having a container in which an inner space of a certain volume is formed and an actuator arranged in the inner space to fore a pumping chamber therein. The actuator comprises a base plate having both sides thereon and a piezoelectric element attached to the base plate. Further provided are a tube having one end connected to the pumping cheer, a nozzle connected to another end of the tube, and an element for controlling a driving voltage applied to the piezoelectric element. For instance, the piezoelectric element is composed of two piezoelectric plates attached each to both the sides of the base plate. A piezoelectric sensor is attached to the base plate for detecting distortion of the actuator, a liquid level of specimens and reagents, and error operations such as air suction and jamming.

Abstract: Piezoelectric elements are attached to both sides of a flexible metal thin plate, thus forming a bimorph-type piezoelectric vibrator. A portion of the metal thin plate is extended to form a stirring blade. A suitable weight is attached to a part of the metal plate such that the amplitude of the blade is made greater than the amplitude of the vibrator itself. The voltage to be applied to the vibrator and the frequency are adjusted, and the vibrator is vibrated in a second-order mode. Thereby, the entire solution is moved simultaneously, vertical motion is caused, and the stirring efficiency is enhanced.

Abstract: A sampling system, favorably applicable to an automatic chemical analyzer, is provided for sampling by sucking and discharging liquid, such as specimens and reagents. The sampling system comprises a pump having a container in which an inner space of a certain volume is formed and an actuator arranged in the inner space to form a pumping chamber therein. The actuator comprises a base plate having both sides thereon and a piezoelectric element attached to the base plate. Further provided are a tube having one end connected to the pumping chamber, a nozzle conntected to another end of the tube, and an element for controlling a driving voltage applied to the piezoelectric element. For instance, the piezoelectric element is composed of two piezoelectric plates attached each to both the sides of the base plate. A piezoelectric sensor is attached to the base plate for detecting distortion of the actuator, a liquid level of specimens and reagents, and error operations such as air suction and jamming.