Locating Leaks on RA-4300FG+

Locating Leaks on RA-4300FG+

This article is to be used when a leak is found on the RA-4300FG+, and the tightening of fittings does not resolve the issue.

1)  Locate the 4mm (outer diameter) tubing that was supplied with the RA-4300FG+.  It is the same size as the tubing used for the argon carrier gas supply into the analyzer.  You will need a 12" section of this tubing.

2)  Open the blue lower front cover of the analyzer and locate the mass flow controller (blue box on left side).  Disconnect the tubing on the right side of the MFC (circled in blue below) by pushing the collar around the tubing toward the fitting while pulling the tubing out and away from the MFC.



3)  Insert one end of the 12" section of 4mm tubing from Step 1 into the fitting circled in blue above.

4)  Disconnect the tubing that exits the silver metal exhaust filter located behind the black detector box as indicated by the blue arrow in the picture below.



5)  There will be a small section of 4mm tubing that is inserted into a section of flexible Tygon tubing, which then connects to the small black flow sensor.  Remove the small 4mm tubing section from the Tygon tubing and insert the free end of the 12" section of 4mm tubing now connected to the MFC.  The argon flow is now bypassing the entire flow path and going straight from the MFC to the flow sensor.

6)  Perform a Leak Check by clicking "Leak Check" under the Run menu in the software.  If the Leak Check now passes, then this confirms a leak in the flow path, and you need to continue to Step 7 below.  If the Leak Check fails with the same failing flow rate as before, then the flow sensor needs to be recalibrated.  Contact AGS Technical Support for assistance with that process.

7)  Only continue from this step forward if the Leak Check in Step 6 passes.

8)  Remove the 12" section of tubing from the flexible Tygon tubing connected to the flow sensor.  Reinstall the small 4mm tubing section removed in Step 5, and re-insert that tubing into the exhaust filter firmly.

9)  Disconnect the elbow fitting circled in blue below from the gold trap by loosening the metal nut and carefully sliding it to the right.  Be careful not to apply pressure downward on the gold trap, as it may break.  With the fitting removed from the gold trap, disconnect the 4mm tubing coming into the bottom of that fitting and connect the 12" section of 4mm tubing in its place.



10)  Carefully, reconnect the elbow fitting to the gold trap, making certain this connection is finger tight and that the gold trap is fully inserted into the union fitting on the left end.

11)  Perform a Leak Check by clicking "Leak Check" under the Run menu in the software.  If the Leak Check now passes, then this confirms the leak is in the flow path between the MFC and this elbow fitting.  Continue to Step 12.  If the Leak Check fails, then the leak is located in the AFS cell or the fittings near it.  Remove the AFS cell and reinstall it per the user manual instructions, then check the tightness of each fitting circled in blue below.  If the fittings are damaged from overtightening, they may need to be replaced.



12)  Repeat Step 9 and disconnect the 12" section of tubing from the elbow fitting.  Reconnect the original tubing to the bottom of the elbow fitting, but do not reconnect to the gold trap yet.

13)  Connect the 12" section of tubing to the bottom of the T-fitting circled in blue below.



14)  Disconnect the other end of the 12" section of tubing from the MFC fitting and reconnect the tubing that was disconnected in Step 2.

15)  Disconnect the 4mm tubing section from the elbow fitting on the lower argon filter (circled in blue below).



16)  Connect the free end of the 12" section of 4mm tubing to this elbow fitting.  Carefully, reconnect the elbow fitting to the gold trap, making certain this connection is finger tight and that the gold trap is fully inserted into the union fitting on the left end.  This will bypass the autosampler area and membrane filter.

17)  Perform a Leak Check by clicking "Leak Check" under the Run menu in the software.  If the Leak Check passes, continue to Step 18.  If the Leak Check fails, then the leak must be in the T-fitting or elbow fitting circled in blue below.  Tighten or replace them to resolve the issue.



18)  Disconnect the elbow fitting from the gold trap (ref. Step 9).  Disconnect the 12" section of 4mm tubing from the T-fitting (ref. Step 13).  Reconnect the original tubing to the T-fitting and reconnect the elbow fitting to the gold trap.

19)  Disconnect the small tubing that enters the membrane dryer tube on the very left side.  It has 4mm tubing as a sheath around this smaller tubing, so make sure to remove both from the fitting (indicated with blue arrow below).



20)  Connect the free end of the 12" section of 4mm tubing to the elbow fitting where the small tubing was just removed in Step 19.  It should now be connected from the elbow fitting on the left side of the lower argon filter to the very left side of the membrane dryer (indicated above in blue).

21)  Perform a Leak Check by clicking "Leak Check" under the Run menu in the software.  If the Leak Check passes, continue to Step 22.  If the Leak Check fails, then the membrane dryer fittings are leaking.  Tighten all fittings for the membrane dryer (large white connectors) very securely.

22)  If the Leak Check has passed all above steps, then the leak is located in the autosampler cap, seal on the sample tubes, or mist catcher.  Inspect and verify that these areas are in good condition and tightly connected.  If the leak cannot be resolved at this point, contact AGS Technical Support for further assistance.

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