Checking for External Leaks on 7697A Headspace

Document created by nkovo Employee on Oct 20, 2020Last modified by nkovo Employee on Nov 3, 2020
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Agilent Support Insights


This Information Applies To:  Agilent 7697A Headspace Sampler



There is a potential leak external to the Headspace unit that can cause loss of pressure.



This article is a troubleshooting guide for when you suspect there is an external leak in the headspace when it is installed on the inlet of a GC.


External Leaks can occur in multiple locations:


• Gas supply bulkhead fittings
• Gas cylinder fittings
• Regulator fittings
• Traps
• Shut- off valves (if installed, not included in ship kit)
• Unions and tee fittings (if installed, not included in ship kit)
• Transfer line connection to the GC


Steps to Follow: 

Safety Warnings : A pressure decay test cuts off carrier flow through the HS and GC. To prevent damage to the flow path components (column, inlet liner, and so forth), cool the HS and GC before beginning.

  1. Cool the HS sample loop, transfer line, and GC inlet and column oven to prevent damage during the test.

  2. Turn off the HS.

  3. Set the regulator pressure to 415 kPa (60 psi).

  4.  Fully turn the regulator pressure adjustment knob counterclockwise to shut the valve.

  5.  Wait 5 min.

  • If there is a measurable drop in pressure, there is a leak in the connections or an internal leak. 
  • No drop in pressure indicates that the external connections are not leaking 



Learn more on how to effectively operate and maintain your 7697A Headspace Sampler:

SI-7697-2100fsV2 - Agilent 7697A Headspace Sampler Operation and Maintenance e-Learning course on Agilent University 



Keywords: GC7697A, pressure drop, pressure error