Trace gas inlet flow & leak check

Purpose: This procedure insures that the trace gas system (NO, NO2, CO, SO2, NOy, NOy*) is leak tight and recording the proper flow rate. It is very important that the gas MFCs are calibrated properly before these tests are completed.

Required Equipment: BIOS with low cell, BIOS tubing, four 9/16” caps,

Reference: SOPMAN

1. Down the gas channels (and met channels if on the same tower) from set flags menu

2. Take down the tower

3. Remove inlet cones

4. Cap inlets with 9/16” caps

5. Record flow rate for CO MFC, SO2 MFC, NO RXN, NO BYP, NOy RXN and NOy BYP MFCs into site log and in the Leak check form in the Tools drop down menu

6. Remove vacuum from the MFCs and record the flow rate into the site log and in the Leak check form in the Tools drop down menu. This is the Pump Off number. Note: You have to remove the vacuum from both of the MFCs that are connected to a single inlet. Ex.: NOy RXN and NOy BYP are on the same inlet so the vacuum has to be removed for both MFCs to get a good Pump Off number (NO RXN & NO BYP are connected to the same inlet. The CO MFC & SO2 MFC are connected to the same inlet).

7. If the difference is +/- 3%, check for loose connections and repeat check

8. Remove caps from inlet

9. Replace vacuum to MFCs

10. Connect BIOS to CO/SO2 inlet

11. Record average of three 10-step Save readings in site log and in the Flow Audit form in the Tools drop down menu

12. Record the 1 minute average of the CO and SO2 MFCs in the site log and in the Flow Audit form in the Tools drop down menu

13. If the difference is +/- 3%, check for loose connections and repeat check.

14. Connect BIOS to NO/NO2 inlet

15. Record average of three 10-step Save readings in site log and in the Flow Audit form in the Tools drop down menu

16. Record the 1 minute average of the NO and NO2 MFCs in the site log and in the Flow Audit form in the Tools drop down menu

17. If the difference is +/- 3%, check for loose connections and repeat check.

18. Connect BIOS to NOy/NOy* inlet

19. Record average of three 10-step Save readings in site log and in the Flow Audit form in the Tools drop down menu

20. Record the 1 minute average of the NOy and NOy* MFCs in the site log and in the Flow Audit form in the Tools drop down menu

21. If the difference is +/- 3%, check for loose connections in the inlet and against the NOy moly converter and repeat check.

22. Save all data in the Flow Audit and Leak Check forms

23. Reconnect the inlet cones to the inlets

24. Raise the tower

25. Up trace gas channels (and Met channels if down)