Dichot Inlet Flow and Leak Check

Purpose:  The Dichot Inlet flow is split into two flows that measure on the DiCoarse filter and DiFine filter.  (You will see these on the ARASiteManager screen.) An inlet flow is compared against these two flow measurements on the DAS.

Required Equipment:  Bios with High Cell

                                           Psychrometer

                                           Inlet flow adapter (same as 5400 and FRM)

Reference: SOPMAN

1. This should be done on a day that the sampler is not running preferably after the sample change-out has been completed. This can also be done in conjunction with PCM and NH3 Inlet Flow/Leak checks.
2. Down the DICOARSE and DIFINE channels via the Set Flags button on the site analyzer screen.
3. Equip the Bios with the High Cell and the inline flow adapter used with the Dichot and FRM.
4. To turn the Dichot on, use the “Set PCM and Dichot Start Dates” prompt found under “Setup” on the toolbar in the ARASiteManager Screen/DAS. Note: This triggers the Dichot, PCM and NH3 pumps.
5. Change the date to today’s date by using the “drop down” arrow and selecting ex: “Today: 4/22/2004. Hit the “Update Sample Start Dates” button.
6. Obtain the “Pump Off” value for the leak check by removing the vacuum side of the Dichot MFC’s. Record this value in your site log.
7. Put these lines back in place and then record (in the site log) the flow rates from the DAS for the DiFine and DiCoarse.
8. Take the BIOS up to the roof.
9. Remove the inlet and set aside.
10. Connect the Bios tubing from the “Outlet” side of the Hi-Flow cell to the inlet using the inlet flow adapter. Be careful that the tubing does not become crimped thus restricting the flow.
11. Turn the BIOS on and wait until the Main Menu appears. Hit the “Enter” key. Hold down both the “Select” and “Enter” buttons on the front of the BIOS at the same time for 2-3 seconds then release to begin recording the flow.
12. Record (in the site log) three “VAve” at 10 cycles from the BIOS.
13. Obtain the temperature from the Psychrometer and the BP from the DAS and record these in the site log.
14. For the leak check, close the flow audit adapter and carefully remove the tubing.
15. Get the leak check information from the DAS when the flow drops down to/near zero. This is considered the “Inlet Capped” value of the leak check.
16. Slowly turn the flow audit adapter until the flow is resumed and take the adapter off.
17. Replace the inlet.
18. Change the “Set PCM and Dichot Start Dates” back to the original date of 1/7/2000 and hit the “Update Sample Start Dates”.
19. With the information that you have obtained, enter the data in the electronic form (which is found on the toolbar under Flow Checks>Flow Audit) under “Dichot Inlet”.