Chromatography Forum

Hello everyone,

I’m experiencing an issue with my Clarus 590 GC related to the split flow and carrier gas stability.

Whenever I set the Split flow above 1 mL/min, it starts to affect the stability of the carrier gas. For example, if I set the Carrier gas flow to 1.0 mL/min and then adjust the Split flow to 2 mL/min, the carrier gas value increase up to around 1.57 mL/min. Shortly after, the system gives an error, triggers an alarm, and then shuts down.

Has anyone encountered this problem before? Do you have suggestions on how to solve or troubleshoot this issue?

Thank you in advance for your help!

Welcome to the forum.

A split slow of 2ml/min is really low, and would not generate the benefits / solve the problems that split injections are designed for. I would guess that it is below the flow rate that the the flow controllers of the GC are designed to handle.

Peter

Peter is correct. The Clarus uses differential in pressure to calculate the split flow. If possible, try not to use split below around 20:1 or ~30 mL/min. You'll know the split flow is too low if pressure drops or flow is hunting while trying to maintain the split. While sometimes you can run lower splits, it's not reliable.