MP-AES 4210, Unstable nebulizer pressure


We have MP-AES 4210. Before opening the plasma, we check the nebulizer pressure. The last few times, it exceeds 500 kPa and the following error appears: "MASSFLOW_GAS_PRESSURE_UNSTABLE_Timed out waiting for stable gas pressure after MFC setpoint change". On the second attempt, the pressure drops to 160 kPa but takes time (over 20 sec) to stabilize.
Does anyone know what could be causing it?

Thank you!

  • What is the type of nebulizer use?  At first glance this look like a bad nebulizer.  What flow are you using when checking the nebulizer flow/pressure.  Also, if it's oneneb you need liquid inside the nebulizer. Peristaltic pump need to run all tubing clamp.   You should check the nebulizer pressure when the plasma is on, and everything is running.  Then compare the pressure overtime to see if the nebulizer is leaking or overpressure.  

    Take a look at your regulator and make sure it's reading the correct range of pressure mark on the instrument.  The pressure is coming from the Nitrogen tank or the generator.  Make sure you are using double stage regulator.  Any fluctuation of the flow on a single stage will trigger fluctuation of the flow has you are taking a lot of flow when plasma is on.  Make sure the clamp is on the peristaltic pump tubing when testing.

    You can try to dip the nebulizer into a beaker of pure water with the gas tubing to check for leaks and behavior.  

  • The nebulizer is OneNeb. I check the pressure at the begining, before opening the plasma. I go to the Dashboard and select "Start" for Nebuizer Test. The flow is 0.70 L/min, I think by Default (I don't know if it can be changed).

    I tried to check the nebulizer pressure when the plasma is on and the pump is running. However, when the plasma is on, I can't select the button "Start" for Nebuizer Test. 

  • Hello,

    Make sure you have the peristaltic pump running and pumping some liquid before you do the nebulizer test. The nebulizer test should not be run all the time, but more when you need to verify if the flow is correct.  Oneneb nebulizer need liquid and tubing clamp before you can run the test.  

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