• Created : 
  • Modified : 
  • Category :  Agilent Knowledge Portal
  • Entry Type :  Article
  • Product Type :  GC Systems
  • Component :  GC Inlets
  • Product Name :  7890 GC System 8860 GC System 8890 GC System
  • Task :  Troubleshooting
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How to Run the Split Vent Restriction Test on 7890 or 8890/8860 GC Systems

Answer

This Information Applies To: 7890 or 8890/8860 GCs with a split/splitless inlet, MMI, PTV inlet, or volatile interface inlet.

Issue

Check the split vent trap line for contamination or an abnormal restriction causing high inlet pressure.

Items Required

  • 1/4-inch wrench

Steps to Follow

To perform the test, you can either have the column installed or the inlet capped.

If you choose to cap the inlet, de-configure the column before starting the test.

For 7890: Run the Inlet Trap Check

  1. On the keypad, press [Service Mode], scroll to Front inlet trap check or Back
    inlet trap check, then press [Enter].
  2. Scroll to Test flow rate and enter a flow rate. A typical flow rate for this test is 400 mL/min, but you may find other values more appropriate for your setup.
  3.  Scroll to Test Inlet and press [On/Yes]. The test will start.
  4.  Wait while the pressure stabilizes. When stable, the Test Inlet line of the display changes to Test pressure OK x.xx, where x.xx is the current pressure. If the inlet cannot achieve the test setpoint, check for a leak (at the inlet, split vent trap, or split vent line) or low supply gas pressure
  5. Note the resulting Inlet Pressure.
  6. Press [Off/No] to stop the test.
   Tips: Typical pressures for a clean split flow path are:

• 1 to 2 psi (7 to 14 kPa) at 400 mL/min for a split liner

• 3 to 10 psi (21 to 69 kPa) at 400 mL/min for a splitless liner

For 8890/8860: Run the Split Vent Restriction Test

  1. On the touch screen display, go to Diagnostics > Diagnostic Tests 
  2. Choose the inlet to test and go to Split Vent Restriction Test. (Figure 1)
  3. Press Start Test.
  4. Follow the instructions that appear on the LUI.


    Split vent restriction test on the Browser Interface of the 8890/8860 GC.
    Figure 1. Split vent restriction test on the Browser Interface of the 8890/8860 GC (actual image might vary depending on GC firmware).

  5. If the test fails and the pressure is higher than expected for a clean system, follow the steps for troubleshooting high inlet pressure in a GC or contact your local Agilent support representative. 
 
Learn how to effectively operate your Agilent 7890, 8860, or 8890 GC: 
Agilent 8860 GC with OpenLab CDS e-learning paths available from Agilent education
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