TPN Audit and Calibration

Purpose: The TPN audit and calibration is to assure that the TPN analyzer/system has the correct gas response. This can be accomplished by introducing a known quantity of gas to the inlet and auditing the response on the instrument. The terminology for this type of audit is GRC (Gas Replacement Calibration). Each GRC has a RF (Response Factor). This RF value should be 1.000 +/- 2%.

Required Equipment: Precision flat head screwdriver

Analyzer Setup

1. The Background (BKG) and Coefficient (COEF) on the analyzer should be set to 0.0 and 1.000 respectively.

2. On the “C” or “CTL” model analyzers press “Menu” and scroll to “Calibration Factors” and press “Enter”. At this point, the parameters should be set as follows: Pre BKG PPB =0.0, NO BKG PPB= 0.0, NOx BKG PPB =0.0, NO COEF =1.000, NOx COEF =1.000 & NO2 COEF =1.000. Press Run when finished.

Analyzer Audit

1. Open the Gas Calibration Worksheet and enter the correct NO concentration (found on the gas cylinder) in the blank provided.

2. In Site Manager go to the Tools tab and select Trigger Cals.

3. In the Trigger Cals menu select TPN Zero and press Start Calibration.

4. Under the Tools tab select Query 1-Minute Data.

5. In the Query Data Tool menu select the Air MFC, Gas MFC, NO3 and TPN.

6. Wait 13 minutes for NO# and TPN are stable. Contact Plano if not stable within 15 minutes. Press Get Data on the query data tool.

7. Enter the Air MFC, NO3 and TPN data in the appropriate blank for the TPN Zero on the Gas Calibration Worksheet in the As Found section.

8. Go to Trigger Cals and press Stop Calibration then select TPN NO GRC Point 1 and press Start Calibration.

9. Wait 13 minutes for NO3 and TPN are stable then press Get Data.

10. Enter the Air MFC, Gas MFC, NO3 and TPN data in the appropriate blanks for the TPN NO GRC Point 1 on the Gas Calibration Worksheet in the As Found section.

11. The RF is now displayed in the worksheet. If the RF is between 0.98 and 1.02, audit is complete. Close the Trigger Cals and Query Data windows.

12. Save the Gas calibration worksheet.

13. If the RF is not within specification continue with the Analyzer Calibration procedure.

Analyzer Calibration

1. Enter the As Found data for TPN Zero in the As Left section for TPN Zero.

2. In Site Manager go to the Tools tab and select Trigger Cals. In the Trigger Cals menu select TPN Zero and wait 5 minutes for data to be captured for First Light use

3. In the Trigger Cals menu select TPN NO GRC Point 1 and press Start Calibration.

4. Under the Tools tab select Query 1-Minute Data.

5. In the Query Data Tool menu select the Air MFC, Gas MFC, NO3 and TPN.

6. Wait 13 minutes for NO3 and TPN are stable.

7. Adjust the instrument to the Actual Expected value from the As Found section of the worksheet.

a. On “C” or “CTL” class analyzers the PMT can be adjusted by taking the top off of the analyzer. With the top of the analyzer off, look on the right side of the bulkhead at the front. There is a blue box with an orange grommet on the top. Inside the grommet is the PMT adjustment screw. Some CTL model analyzers have been modified so that the PMT can be adjusted through the front panel. Adjust the analyzer until the NO channel on the analyzer or CH1 on Site Manager is approximately equal to the Actual Expected value from the As Found section worksheet.

8. When the analyzer calibrations are complete, let the analyzer stabilize for 5 minutes.

9. On the Query 1-Minute Data tool press Get Data.

10. Enter the Air MFC, Gas MFC, NO3 and TPN data in the appropriate blank for the TPN NO GRC Point 1 on the Gas Calibration Worksheet in the As Left section.

11. The RF is now displayed in the worksheet. If the RF is between 0.98 and 1.02, the calibration is complete. If the RF is not within specification, repeat the calibration part of the procedure again.

12. When the instrument is finished being calibrated make sure to put it back into the Run mode.

13. Close the Trigger Cals and Query Data windows.

14. Save the Gas Calibration worksheet.

TPN Conversion Efficiency Audit

1. This procedure will obtain the current RF value for the NO2 Conversion Efficiency.

2. Open the Gas Calibration Worksheet and go to the NO2 Conv Eff Worksheet tab. Enter the correct NO and NO2 concentrations (found on the gas cylinder) in the blanks provided.

3. An NO audit of the analyzer has to be completed before the NO2 conversion efficiency can be completed. You may use that day’s information if available. If it is available enter the information and start with Step 15. Otherwise continue with the next Step.

4. On the Site Manager screen go to the Tools tab and select Trigger Cals.

5. In the Trigger Cals menu select TPN Zero and press Start Calibration.

6. Under the Tools tab select Query 1-Minute Data.

7. In the query data tool menu select the Air MFC, Gas MFC, NO3 and TPN.

8. Wait 13 minutes and verify the Zeros for NO3 and TPN are stable (+/-0.1 ppb). Contact Plano if not stable within 15 minutes. Press Get Data on the Query Data Tool.

9. Enter the Air MFC, NO3 and TPN data in the appropriate blank for the TPN Zero on the NO2 Conv Eff Worksheet in the TPN Analyzer Response section.

10. Go to Trigger Cals and press Stop Calibration then select TPN NO GRC Point 1 and press Start Calibration.

11. Wait 13 minutes and verify the data for NO3 and TPN are stable (+/- 0.2ppb), then press Get Data.

12. Enter the Air MFC, Gas MFC, NO3 and TPN data in the appropriate blanks for the TPN NO GRC Point 1 on the NO2 Conv Eff Worksheet in the TPN Analyzer Response section.

13. The RF is now displayed at the far right of the worksheet.

14. Save the Gas Calibration Worksheet.

15. In the Trigger Cals menu select TPN Zero and press Start Calibration.

16. Under the Tools tab select Query 1-Minute Data.

17. In the query data tool menu select the Air MFC, Gas MFC, NO3 and TPN.

18. Wait 13 minutes and verify the Zeros for NO3 and TPN are stable (+/-0.1 ppb). Contact Plano if not stable within 15 minutes. Press Get Data on the Query Data Tool.

19. Enter the Air MFC, NO3 and TPN data in the appropriate blank for the TPN Zero on the NO2 Conv Eff Worksheet in the TPN NO2 Conversion Efficiency section.

20. Go to Trigger Cals and press Stop Calibration then select TPN NO2 GRC Point 1 and press Start Calibration.

21. Wait 13 minutes and verify the data for NO3 and TPN are stable (+/- 0.2ppb), then press Get Data.

22. Enter the Air MFC, Gas MFC, NO3 and TPN data in the appropriate blanks for the TPN NO2 GRC Point 1 on the NO2 Conv Eff Worksheet in the TPN NO2 Conversion Efficiency section.

23. The RF is now displayed at the far right of the worksheet.

24. If the RF is less than 0.95 it is out of spec and the RF will turn red.

25. Contact Plano if the RF is out of spec.

26. Close the Trigger Cals and Query Data windows.

27. Save the Gas Calibration Worksheet.