Dionex Softron Gmbh

Dionex Softon Gmbh

Christoph Strobl

Erik Baigar

Michael Haeckel

Stefan Seitz

A control device of a piston pump unit comprising at least two piston-cylinder units that operate in a phase-shifted manner for the purpose of liquid chromatography and to a piston pump unit is described. The control device corrects fluctuations of the system pressure while switching from one piston cylinder unit to the respective other piston cylinder unit. The fluctuations can occur as a result of the cooling of the liquid medium that is heated in an adiabatic manner during a pre-compression phase in the working piston. The control unit controls the piston speed of at least one piston-cylinder unit during the transition phase depending on at least one characteristic, which is ascertained from chronologically previously detected pressure values, such that variations of the system pressure as a result of the cooling of the adiabatically heated medium are at least partially compensated for.

Device for controlling a piston pump unit for liquid chromatography

The present invention relates to a method comprising using an acoustic wave in a chromatography system. The present invention also relates to a corresponding system and a corresponding use. The system may comprise a surface acoustic wave assembly, wherein the surface acoustic wave assembly comprises a sender unit comprising a sender transducer for sending an acoustic wave and a detection unit for detecting the acoustic wave, a substrate configured for propagation of the acoustic wave, wherein the sender transducer is connected to the substrate, wherein the substrate comprises a substrate section for propagation of the wave from the sender transducer, wherein this substrate section comprises a substrate surface, wherein the surface acoustic wave assembly further comprises at least one channel for conducting fluid, wherein this channel is partly defined by the substrate surface.

Use of an acoustic wave in a chromatography system

The present invention relates to a method of operating a pump generating a flow of a fluid with a pressure, the method comprising operating the pump with a pump speed S satisfying the equation S=S(1+COR(t)); wherein S is the pump speed, Sis the pump speed disregarding any compression and/or expansion of the fluid, t is a time, and COR(t) is a time dependent correction function; wherein the time dependent correction function COR(t) is a product of a corrective amplitude Aand a time-dependent function f(t), i.e., COR(t)=A&#xb7;&#x192;(t); and wherein the corrective amplitude Acor is set based on a measure for the flow and a measure for the pressure. The present invention also relates to a corresponding use, a pump, a pump system and an HPLC system.

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Munich, Germany

Christoph Strobl