CO/SO2 Zero Baseline and Response Check/Adjustment

 

Purpose:  The CO/SO2 zero baseline and response check/adjustment assures that the CO and SO2 analyzers have the correct gas calibration.  This can be accomplished by introducing a known quantity of gas to the inlet and checking the response on the instrument.  The terminology for this type of check is GRC (Gas Replacement Calibration).  Each GRC has a RF (Response Factor).  This RF value should be 1.000. 

 

Required Equipment:  Precision flat head screwdriver

 

Reference:  SOPMAN Pages XX-XX

 

 

CO Analyzer Zero Baseline Check/Adjustment

 

1.        Open the Gas Calibration worksheet.

2.        On DataView go to the tools tab and select Trigger Cals.

3.        In the trigger cals menu select CO Zero and press Start Calibration.

4.        Under the tools tab select Query 1-Minute Data.  In the query data tool menu select CO.

5.        Enter the Background (BKG) number onto the Gas Calibration worksheet in the Zero Baseline Adjustment section.  The number should be entered in the as found column.

6.        To find the BKG number on a 48CTL analyzer scroll down to Calibration Factors and press enter.  Then scroll to CO BKG PPM and press enter.  The top number is the PPM (Parts Per Million) number for the analyzer and the bottom number is the BKG number.  (Note:  The analyzer reads in PPM and the DAS reads in PPB.  If the analyzer is 0.500 PPM the DAS should read 500 PPB.)

7.        Wait 7-10 minutes or until the CO number is stable.  Press Get Data on the query data tool.  If the query data numbers are larger or approximately equal to the number on DataView then the data is stable and an average can be taken.

8.        Enter the CO data in the as found Zero Baseline Adjustment section of the Gas Calibration worksheet.  The DAS number should be approximately 200 PPB and the analyzer should be approximately 0.200 PPM.  If it isn’t, adjust the BKG or Zero Pot.

9.        The 48CTL analyzer should already be in the adjustment screen (follow step 6).  Use the up and down arrows to adjust the Background number so that the DAS CO number is ~200 PPB or the analyzer is ~0.200 PPM.  When this is complete press enter on the analyzer.

10.     Record the final BKG and/or Zero Pot number in the as left cell of the Gas Calibration worksheet.

11.     On the query data tool press Get Data and enter the CO number in the as left cell of the Gas Calibration worksheet.

12.     Press Run or Auto on the analyzer and close the Trigger Cals Menu.

 

 

SO2 Analyzer Zero Baseline Check/Adjustment

 

1.        Open the Gas Calibration worksheet.

2.        On DataView go to the tools tab and select Trigger Cals.

3.        In the trigger cals menu select CO/SO2 Zero and press Start Calibration.

4.        Under the tools tab select Query 1-Minute Data.  In the query data tool menu select SO2.

5.        Enter the Background (BKG) or Zero Potentiometer (Zero Pot) number onto the Gas Calibration worksheet in the Zero Baseline Adjustment section.  The number should be entered in the as found column.

a.        To find the BKG number on a 43CTL analyzer scroll down to Calibration Factors and press enter.  Then scroll to SO2 BKG PPB and press enter.  The top number is the PPB (Parts Per Billion) number for the analyzer and the bottom number is the BKG number.

b.       On a 43S analyzer the Zero Pot is on the front of the instrument.  Read the number in the window then the number on the hash marks and then count the number of hash marks from the main number to the pointer.  (Ex.:  window = 2, main hash mark number = 7, the number of hash marks from the main number to the pointer = 4 – From this information the Zero Pot number is 2.74.)

6.        Wait 7-10 minutes or until the SO2 number is stable.  Press Get Data on the query data tool.  If the query data numbers are larger or approximately equal to the number on DataView then the data is stable and an average can be taken.

7.        Enter the SO2 data in the as found Zero Baseline Adjustment section of the Gas Calibration worksheet.  The PPB number should be approximately 1.00.  If it isn’t, adjust the BKG or Zero Pot.

a.        If you have a 43CTL analyzer it should already be in the adjustment screen (follow step 6).  Use the up and down arrows to adjust the Background number so that the SO2 PPB number is ~1.00.  When this is complete press enter on the analyzer.

b.       On a 43 S analyzer adjust the Zero Pot until the SO2 PPB reading is approximately 1.00.

8.        Record the final BKG and/or Zero Pot number in the as left cell of the Gas Calibration worksheet.

9.        On the query data tool press Get Data and enter the SO2 number in the as left cell of the Gas Calibration worksheet.

10.     Press Run or Auto on the analyzer and close the Trigger Cals Menu.

 

 

CO/SO2 Analyzer Response Check

 

1.        This procedure will obtain the initial or current RF value for the CO and SO2 analyzers.

2.        Open the Gas Calibration Worksheet and enter the correct CO and SO2 concentrations (found on the gas cylinder) in the blank provided.

3.        On DataView go to the tools tab and select Trigger Cals.

4.        In the Trigger Cals menu, select CO/SO2 Zero and press Start Calibration.

5.        Under the tools tab select Query 1-Minute Data.  In the query data tool menu select Air MFC, Gas MFC, CO and SO2.

6.        Wait 20 minutes or until the data for CO isn’t changing by more than 3 PPB per minute and the SO2 isn’t changing by more than 0.05 PPB per minute.  This is so that the instruments can equalize before going on to the next step.

7.        Press Get Data on the query data tool.  If the query data numbers are approximately equal to the number on DataView then the data is stable and an average can be taken.

8.        Enter the Air MFC, CO and SO2 data in the as found section of the Gas Calibration worksheet.

9.        Go to Trigger Cals and push Stop Calibration then select CO/SO2 GRC Point 1 and press Start Calibration.

10.     Wait 7-10 minutes or until the data for CO and SO2 are stable.  Press Get Data on the query data tool. 

11.     Enter the Air MFC, Gas MFC, CO and SO2 data in the as found section of the Gas Calibration worksheet.  Also enter the COEF and/or Span Pot number. 

a.        To find the COEF (Coefficient) on a 48CTL CO analyzer scroll down to Calibration Factors and press enter.  Then scroll to CO COEF and press enter.  The top number is the PPM (Parts Per Million) number for the analyzer and the bottom number is the COEF number.

b.       To find the COEF (Coefficient) number on a 43CTL analyzer scroll down to Calibration Factors and press enter.  Then scroll to SO2 COEF and press enter.  The top number is the PPB (Parts Per Billion) number for the analyzer and the bottom number is the COEF number.

c.        On a 43S analyzer the Span Pot is on the front of the instrument.  Read the number in the window then the number on the hash marks and then count the number of hash marks from the main number to the pointer.  (Ex.:  window = 2, main hash mark number = 7, the number of hash marks from the main number to the pointer = 4 – From this information the Zero Pot number is 2.74.)

12.     Go to Trigger Cals and press Stop Calibration then select CO/SO2 Zero and press Start Calibration.

13.     Wait 7-10 minutes or until the data for CO and SO2 are stable.  Press Get Data on the query data tool.

14.     Enter the Air MFC, CO and SO2 data in the as found section of the Gas Calibration worksheet.

15.     The Actual Expected value is calculated by adding the final Zero Value and Calculated Expected Value.

16.     The RF is now displayed at the far right of the worksheet.  If the RF is between 0.98 and 1.02, the calibration check is complete. 

17.     Close the trigger cals window and query data window.

18.     Save the Gas calibration worksheet, and then print the CO and SO2 Response information and fax to Plano.  (Note: you can wait until the response checks for all analyzers are complete before faxing to Plano.)

19.     If either RF is not within the specified range continue with the Analyzer Response Adjustment.

 

 

CO/SO2 Analyzer Response Adjustment

 

1.        This procedure will be used to adjust the analyzers and obtain a corrected RF value for the CO and SO2 analyzers.

2.        Using the as found data for the CO/SO2 Zero, enter the Air MFC, CO and SO2 values in the as left section.

3.        On DataView go to the tools tab and select Trigger Cals.

4.        In the Trigger Cals menu, select CO/SO2 GRC Point 1 and press Start Calibration.

5.        Under the tools tab select Query 1-Minute Data.  In the query data tool menu select Air MFC, Gas MFC, CO and SO2.

6.        Wait 7-10 minutes or until the data for CO and SO2 are stable.

7.        Adjust the instruments.

a.        On 48CTL CO analyzers push menu.  Scroll down to CAL FACTORS and push ENTER.  Go to the CO COEF and press enter.  The top number is the PPM (Parts Per Million) number for the analyzer and the bottom number is the COEF number.  Use the up and down arrows to adjust the COEF number so that the DAS CO PPB number approximately equal to the Actual Expected value from the as found section.  When this is complete press enter on the analyzer.    

b.       On 43CTL analyzers push menu.  Scroll down to CAL FACTORS and push ENTER.  Go to the SO2 COEF and press enter – Set the SO2 COEF to 1.0.  The PMT can be adjusted by taking the top off of the analyzer.   With the top of the analyzer off, look on the left 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.  Slowly adjust the analyzer until the SO2 ppb on the analyzer, or SO2 on DataView, is approximately equal to the Actual Expected value from the as found section.  The PMT adjustment screw on the inside of the analyzer is a coarse adjustment and the SO2 COEF is a fine adjustment.  The SO2 COEF should always be close to a standard of 1.00 but it can be used to adjust the instrument to a tighter tolerance.  The SO2 COEF will adjust the instrument in smaller increments than the PMT adjustment.  Replace the top of the analyzer.

c.        On 43S analyzers set the Span Pot to 5.00.  Open the front door on the analyzer and slowly adjust the PHOTOMULTIPLIER GAIN screw until the SO2 reading on the analyzer, or SO2 on DataView, is approximately equal to the Actual Expected value from the as found section.  The PMT adjustment screw on the inside of the analyzer is a coarse adjustment and the Span Pot is a fine adjustment.  The Span Pot should always be close to a standard of 5.00 but it can be used to adjust the instrument to a tighter tolerance.  The Span Pot will adjust the instrument in smaller increments than the PMT adjustment.

8.        When the analyzer adjustments are complete, let the analyzers stabilize for 7-10 minutes.  Press Get Data on the query data tool.

9.        Enter the Air MFC, Gas MFC, CO and SO2 data in the as found section of the Gas Calibration worksheet.  Also enter the COEF and/or Span Pot number.

10.     The Actual Expected value is calculated by adding the final Zero Value and Calculated Expected Value.

11.     The RF is now displayed at the far right of the worksheet.  If the RF is between 0.98 and 1.02, the calibration adjustment is complete.  If the RF is not within spec, repeat the adjustment part of the procedure again.

20.     Go to Trigger Cals and press Stop Calibration then select CO/SO2 Zero and press Start Calibration.

21.     Wait 7-10 minutes or until the data for CO and SO2 are stable.  Press Get Data on the query data tool.

22.     Enter the Air MFC, CO and SO2 data in the as left section of the Gas Calibration worksheet.

23.     Close the trigger cals window and query data window.

24.     Save the Gas calibration worksheet, and then print the CO and SO2 Response information and fax to Plano.  (Note: you can wait until the response checks for all analyzers are complete before faxing to Plano.)