Dionex As - Selecting Syringe Speed Settings

AS Autosampler Operator’s Manual
92 Doc. 065051-03 1/08
3.7 Selecting Syringe Speed Settings
The speed at which the sample syringe and prep syringe move can vary between a
speed of 1 (the slowest) to 5 (the fastest). You can select syringe speeds on the
Chromeleon or Chromeleon Xpress Control panel (see Section 3.7.1
) and in the
Program Wizard or Program Editor (see Section 3.7.2
).
Controlling the Backpressure
The AS is capable of delivering at a maximum pressure of 690 kPa (100 psi). The
syringe speed affects the backpressure produced at the inject port and needle seal;
a faster syringe speed produces more backpressure than a slower speed.
Other factors that affect the backpressure:
• The syringe size.
• The tubing IDs and lengths.
• The sample viscosity. Select a slower speed (1 or 2) for viscous samples.
• The presence of a concentrator column. If a concentrator column is installed,
a speed of 1 or 2 is required.
Refer to Section 3.8
to select the appropriate syringe speed, syringe size, and
tubing IDs to keep the total backpressure below 690 kPa (100 psi)
Selecting Separate Aspirate and Dispense Speeds
If you are using Chromeleon or Chromeleon Xpress (Release 6.8 SP2, or later) to
control the autosampler, you can specify separate syringe speeds for aspirating
and dispensing liquid during the following functions: Flush, Prime, Load, Reagent
Flush, Reagent Prime, and Concentrate. For example, if the AS is loading sample,
you can select a faster syringe speed for aspirating sample from the vial and a
slower speed for dispensing sample to the loop or concentrator column.
Notes
• If the AS is running under Local (front panel) control and is never connected
to Chromeleon or Chromeleon Xpress Release 6.8 SP2 (or later), the aspirate
and dispense speeds are always the same. See Section D.7
for details about
selecting syringe speeds for front panel operation.
• If the AS is connected to Chromeleon or Chromeleon Xpress Release 6.8 SP1
(or earlier) or if Moduleware Version 2.01 (or earlier) is installed, different
aspirate and dispense speeds are not supported.