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- Posts: 8
- Joined: Tue Jul 11, 2017 4:56 pm
We have an Agilent GC/MS 7890A/5975C running in PCI mode with isobutane that is giving us some grief. In a previous post, I indicated an intermittent "step-like" baseline disturbance and short filament lifetime. We thought we fixed the issue after swapping the repeller insulator on the source, but the issue returned with a vengeance and we are now experiencing a complete failure in some part of the CI module that is preventing operation in CI mode. We get the error message "CI Flow Controller is not controlling reagent properly" for both methane and isobutane, and a flow and pressure reading of -1. It is running beautifully in EI mode.
Our independent service engineer (we do not have a service contract with Agilent) thinks the issue is the mass flow controller. However, because the CI module has been upgraded, Agilent no longer sells the mass flow controller we need. They have indicated our only option is for Agilent to come replace the entire CI module. Our module is only five years old.
We are hoping to try some alternative options before throwing out the baby with the bathwater. We are not 100% sure it's the mass flow controller, since we don't have a replacement part to test. Any ideas for what else could be going on, and how we could test it? Could it possibly be a failed valve or gasket? Also, any suggestions for reputable sources for used parts? Would be it possible to buy a mass flow controller from a third party, or is compatibility strictly limited to Agilent's products?
Thank you, I know this is probably a reach. Let me know if I can provide additional information.