Noisy baseline seen using THF on ACQUITY RI detector in an APC system - WKB112175

SYMPTOMS

• Noisy baseline observed using THF on ACQUITY RI detector in APC system 
• Solvent manager dynamic leak test successful but with a higher than expected leak rate (200 nL/min) for the primary head
• Consistent negative spikes at regular intervals in RI trace at low flow

ENVIRONMENT

• ACQUITY APC Isocratic Solvent Manager
• ACQUITY UPLC RI Detector

CAUSE

The primary check valve is not operating effectively at low pressures when pumping THF.

FIX or WORKAROUND

Replace the primary check valve (700004139).

ADDITIONAL INFORMATION