The time waiting for QSM message varies with flow rate on ACQUITY Arc QSM-R - WKB69587

SYMPTOMS

• Waiting for QSM message after sampling has occurred and before injection
• When the error appears is affected by the flow rate

ENVIRONMENT

• ACQUITY Arc QSM-R

CAUSE

The Arc system uses quantum sync. This means that the QSM is in control of when the injection actually occurs.

The QSM will only trigger the injection when at a certain point in the pump stroke cycle.

This provides the most consistent gradient production and therefore provides the most consistent retention time.

The time the pump takes to reach the specific point in its cycle depends on flow rate and stroke volume settings.

If flow rate is very low and a high stroke volume setting is used, it is possible for the pump to take a number of minutes to reach the required point in its cycle to trigger the injection.

FIX or WORKAROUND

None required. This is normal behavior.

ADDITIONAL INFORMATION