Tekran Leak Check

 

Purpose:  Leak checking the sample flow stream of the Tekran.  The procedure is in two parts:  operational leak check and troubleshooting leak check.

 

Required Equipment:  ¼” Teflon TEE & associated nuts & ferrules                                     

 

Reference:  SOPMAN Pages XX-XX

 

After changing the sample filters, denuder, soda lime trap or the RPF a leak check must be done to make sure the sample circuit is leak tight. 

 

 

Operational Leak Check

 

  1. After any maintenance to the sample circuit, perform a leak check.
  2. Put the Tekran back into normal run mode.  It should start up in Hg (0) mode.
  3. Let the system run for approximately 15 minutes.
  4. Check the data for equilibrium.  The data will be settled enough to complete the leak check once the last two data points for the concentration are between 1 and 3.  Follow the following steps to open the database. 
    1. To do this open MS Access. 
    2. When it opens it will give a group of file names usually on the right side of the screen under the Open a File header. 
    3. Select the file named SiteManager.
    4. Double click on the data table named Tekran Data.
  5. If the concentration doesn’t stabilize contact Plano.
  6. Go to the 1130 pump module and turn the Pump switch to Desorb.  This will change the inlet from 10 LPM to 1 or 1.25 LPM.
  7. Go to the 1130 pump module and turn the Zero Air switch to the On position.  This will force the 1130 to pump enough zero air to overflow the inlet.
  8. Wait for approximately 10-15 minutes and then check the data.  The concentration should be 0.0.
  9. If the concentration is 0.0 the sample circuit is leak tight.  Restore the Tekran to normal operation by turning the Pump switch to Sample and the Zero Air switch to Auto.
  10. If the concentration isn’t 0.0 then there may be one of two possible issues.  One is there may be a leak and the second is that the glassware may be contaminated.  To determine which issue the Tekran has go to the Troubleshooting Leak Check section.

 

 

Troubleshooting Leak Check

 

Section A

This section is leak checking from the 1130 denuder module sample filter downstream to the 2537 analyzer.  If 0.0 is not obtained through the Operational Leak Check follow the following steps to determine if it is a leak or contamination.

 

  1. Determining where the issue is or the severity of the issue will take a couple of modifications to the system.
  2. Disconnect the sample filter in the 1130 denuder module.  Disconnect it on the upstream side of the filter (top side of the filter).  Below it a photo of the Denuder Module.  The Yellow arrow points to the location where the filter needs to be disconnected.
  3. Attach a teflon TEE to the top of the filter.
  4. From the TEE run a piece of teflon tubing from the zero air port on the bottom of the 1130 denuder module to one side of the TEE.  Leave the other side of the TEE open.
  5. Start the flow of zero air to the system as was done in the Operational Leak Check section by turning the 1130 pump module Pump switch to Desorb and the Zero Air switch to On.
  6. Open the data base and check the concentration for 0.0.  It may take 10-15 minutes for the system to stabilize.
  7. If the concentration is 0.0 then the issue isn’t a leak from the 1130 denuder module sample filter to the 2537 analyzer.  There could be contamination and/or a leak further upstream from the filter.  Put the system back together, turn the Pump switch back to Sample and the Zero Air switch back to Auto and let it run overnight to burn in.  Check it the following day using the Operational Leak Check method.
  8. If the concentration is not 0.0 then there is a leak in the sample filter or downstream of the sample filter.  Go to Section B.

 

 

 

Section B

This section will test for a leak in the 1130 denuder module sample filter and downstream of the sample filter.

 

1.        If there is a leak in the system and the first part of the troubleshooting section has been completed then the leak is in the sample filter or downstream of the sample filter.

2.        To determine whether the leak is in the sample filter pack, connect a teflon TEE to the tubing on the downstream side of the sample filter pack.

3.        From the TEE run a piece of teflon tubing from the zero air port on the bottom of the 1130 denuder module to one side of the TEE.  Leave the other side of the TEE open.

4.        Start the flow of zero air to the system as was done in the Operational Leak Check section by turning the 1130 pump module Pump switch to Desorb and the Zero Air switch to On.

5.        Open the data base and check the concentration for 0.0.  It may take 10-15 minutes for the system to stabilize.

6.        If the concentration is 0.0 then the leak is in the sample filter pack.  Check the filter for tears along the edges and tighten the sample filter pack.  Test it as was done in the previous steps but attach the TEE to the top or upstream side of the sample filter pack.  If the concentration is 0.0 put the system back together and use the Operational Leak Check to test the entire system.  If the concentration is not 0.0, remove the sample filter pack and clean it with 91% Isopropyl Alcohol, rinse with DI water, dry and retest.

7.        If the concentration is not 0.0 then there is a leak on the system in the shelter.

8.        To test for a leak in the shelter attach the teflon TEE to the tubing which is connected to the bottom of the sample filter on the 2537 analyzer.  The figure below will show the connection points.

9.        Disconnect the zero air supply tubing from the umbilical and attach it to the TEE leaving one side of the TEE open to shelter air.  Turn the zero air On and turn the pump switch to Desorb.  Check for a concentration of 0.0 which tests only the 2537 analyzer.  If the concentration isn’t 0.0 there is an issue inside the 2537 analyzer.  Contact Plano for further assistance.

10.     If the concentration from the last step is 0.0 then the leak is not in the 2537.  It is in the soda lime trap or the 1130 pump module.

11.     To test the soda lime trap disconnect the tubing coming from the pump module to the TEE on the upstream side of the soda lime trap and connect the zero air line to the TEE.  Turn the zero air On and turn the pump switch to Desorb.  Check for a concentration of 0.0. 

12.     If it is not 0.0 the leak is either in the TEE or in the Soda Lime trap.  Tighten all fittings and test again.  If it is not 0.0 the soda lime trap may be contaminated or leaking and will have to be cleaned or replaced.

13.     To clean the soda lime trap remove the soda lime trap and fittings and attach the zero air line to one end.  Turn on the zero air and let it flow thru the soda lime trap for several minutes, then repeat steps 11 & 12.  If this doesn’t pass the test then replace the soda lime trap. 

14.     If the concentration is 0.0 the leak is in the 1130 Pump Module.    

15.     To test for a leak in the pump module turn the pump switch to sample cap the Sample In port on the pump module.  The flow should go to 0.0.

16.     If it doesn’t go to 0.0 tighten all fittings both inside and out until the flow goes to 0.0.

17.     If the flow won’t go to 0.0 there could be a leaky component inside the 1130 pump module.  Check the zero air scrubbers and associated Balston filters for leaks.  If the flow still does not go to 0.0 contact Plano for further assistance.