17.3.3.2 Pumps These are piston-type precision pumps.
They pump the polymer in solution through the system. The
pump must deliver the same flow rates throughout the time
in order to maintain the same pressure inside the system.
Any variation in flow rates affects directly the results. The
pump also has to deliver the same flow rates independently
of the viscosity differences. In addition, some detectors are
highly sensitive to the solvent flow rate precision. Such
constant flow is a critical feature of the instrument.