General Information
The pump is a serial dual-piston pump with electronic compressibility compensation for precise and virtually pulse-free flow.
The pump head comprises a working cylinder and an equilibration cylinder that are connected in series. Thus, the solvent passes both cylinders successively. To achieve continuous delivery, the working cylinder delivers while the equilibration cylinder is filled simultaneously. The equilibration cylinder serves as the reservoir and delivers while the working cylinder performs the intake stroke.
When delivering compressible liquids without controlled pre-compression, pulsation increases along with the increasing working pressure because part of the delivery stroke is required for compressing the liquid in the working cylinder. Pulsation during the pre-compression phase is reduced to a minimum by velocity modulation of the drive. Highly constant delivery is ensured by a patented secondary control system (automatic compressibility compensation). Independent of the operating pressure, the flow rate of the solvent (after expansion to atmospheric pressure) is always kept constant.
Pump-Specific Information
Pumps with vacuum degasser
The vacuum degasser enhances the flow stability and allows best detector sensitivity by continuously removing dissolved gasses that may be trapped in the solvents.
Pumps with mixing system
The mixing system ensures smoother baselines by combining and premixing the solvent streams in the capillary mixer and improving the mixing quality further in the static mixer.
For pump-specific pictures that illustrate how the pump operates, see Pump-Specific Information.