TEOM Inlet Flow and Leak Check

Purpose: Flow and leak checks confirm that air is flowing through the inlet and into the TEOM at prescribed rates. Flow errors at the inlet may cause particles of the wrong size to be measured, while other flow errors may cause particle concentration to be calculated improperly. Main flow should always be 3.00 +/- 0.05 lpm. Auxiliary flow should be at 13.70 +/- 0.05 lpm. The sum of main flow and auxiliary flow should therefore always be in the range 16.6 to 16.8 liters per minute.

Required Equipment: Bios with high and standard cells

Reference: SOPMAN

1. Down the TEOM channel on the DAS. Remove the TEOM inlet from the flow splitter and gently place on the shelter deck. Verify that the flow check adapter is open and connect to the flow splitter.

2. Connect the BIOS to the flow check adapter, begin acquiring flow data and observe the average readings. When the averages have stabilized (within +/- 0.1 lpm), record 3 10-count S-ave readings. This reading should be 16.7 lpm.

3. Return to the shelter and record main and auxiliary flows displayed by the TEOM. The main flow should be 3.00 lpm and the auxiliary flow at 13.7 lpm +/- 0.10 lpm. If these flows are out of specification, confirm that the MFCs are recording the actual flow rate by hooking the bios up to the main or aux MFC directly and comparing to the DAS.

4. Shut off the flow check adapter to perform a leak check. Wait 3 minutes, and then record the main and auxiliary MFC flows displayed by the DAS. These flows should be 0.00 +/- 0.05 lpm.

5. Compare these readings to the main and aux MFC reading when the vacuum line is removed. If they are different, the MFCs may need calibrating (reference the MFC calibration SOP).

6. Slowly open the flow check adapter until you begin to hear a hissing sound. Continue to open the valve until half way between vertical and horizontal. Wait 10 seconds, and then open the valve completely.

7. Remove the flow check adapter and reconnect the inlet. Make sure the inlet is fully seated on the flow splitter.

8. Enter flow and leak check readings in the site log and Site Manager Flow audit form. If main flow is outside the range 2.90 to 3.10 slpm or if total flow is outside the range 16.3 to 17.1 slpm, and the MFC is not out of calibration, close the SM ticket and create a new operations ticket explaining the issue and what has been done so far.