Dionex UltiMate 3000 Series, Руководство по эксплуатации

Страница: 135 / 236

UltiMate 3000 Series:
SD, RS, and BM Pumps
Operating Instructions Page 121
6.6 Checking the Compression Values
The compression value of the pump head can provide valuable information for
troubleshooting. If you observe pump pulsation and/or shifts in retention times, check the
compression values:

On the pump display, select the Diagnostics menu and Compression right or
Compression left .

In Chromeleon, open the Commands dialog box for the pump and select [Pump Device
Name]_Wellness_LeftBlock and Compression or [Pump Device
Name]_Wellness_RightBlock and Compression . (For information about the [Pump
Device Name], see page 37.)
The values are indicated in per cent and show the compression of the last stroke. The
compression value should be lower than 100% and remain stable. If the value is close to
100%, the required precompression may not be reached and pulsation may occur.
The table shows guides values for some solvents:
Solvent Compression*
RS pumps SD pumps BM pumps
Acetonitrile
45 %

10 % 70 %

10 % 75 %

10 %
Methanol
50 %

10 % 70 %

10 % 80 %

10 %
Water
25 %

10 % 50 %

10 % 55 %

10 %
* with 100 % of degassed solvent delivered at 40 MPa, pump purged and stable for some time
The values are linear to the pressure.

If the compression value is lower than indicated in the table, the cartridge in the valve
cartridge (outlet check valve) may be defective. Replace the cartridge (

page 128).

If the compression value is higher than indicated in the table

The piston seals may be defective. Replace the piston seals (

page 139).

The valve cartridge (inlet check valve) may be defective. Replace the cartridge
(

page 128).

If the compression is very high and the pressure is low, there may be air bubbles in the
system. Purge the pump (

page 54).