Optimizing Viscometer Performance - Agilent Technologies 1260 Infinity User Manual

6
Optimizing Performance

Optimizing Viscometer Performance

Optimizing Viscometer Performance

The Agilent 1260 MDS Viscometer employs the fluid flow equivalent of the
analogous Wheatstone bridge electrical circuit; see
Viscometer"
When mobile phase is pumped into the viscometer, solvent travels down a
bridge of four capillaries of equal resistance. However, when the sample is
introduced an imbalance is created. This change in pressure, ΔP, is
proportional to the specific viscosity and the instrument makes a true
differential measurement directly, making it very sensitive to changes in
viscosity.
Consequently, the performance of the viscometer is highly dependent on
the pump performance. The solvent delivery module must be thoroughly
purged, and able to deliver solvent at the desired flow rate without
pulsation.
Viscometer performance is also dependent on how thoroughly the detector
has been purged. Any air bubbles or residual traces of previous solvent in
the system will result in poor results. It is therefore important to follow
the purging procedures that are described in this manual and allow
enough time for the detector to equilibrate in the desired solvent.
112
on page 163 for detailed theory of operation.
"The 1260 Infinity MDS
Agilent MDS User Manual