Calibrating the Mass Flow Controller

Under normal circumstances the mass flow controller (MFC) should not need to be calibrated by you, the customer. Calibration is done at TA Instruments for you. If you need to return the calibration values to their factory settings for any reason, select Calibrate/Mass Flow Control to view the calibration tables. Select the desired table, then click the Restore Values button and the original calibration values will be restored.

If you decide that you need to calibrate the MFC, follow the calibration instructions below or call TA Instruments for service. An external high-precision flow meter is required to calibrate for both nitrogen and helium. (Two separate flow meters may be needed, one calibrated for nitrogen and the other for helium.)

To calibrate the mass flow controllers, follow these directions for either the Nitrogen Tables or Helium Tables.

NOTE: Please make sure that you run your experiments with the same gas that you used to calibrate the system. For example, if you calibrate using nitrogen, make your runs with nitrogen.

Calibrating the MFC Nitrogen Tables

This table is used to enter the calibration values for nitrogen.

1. Select Calibrate/Mass Flow Controller. Click on the Nitrogen Table tab.

2. Click the Reset button to set the observed values to zeroes. The Requested Flow and Measured Flow values will display the recommended flow rates for calibration. These values may be changed, if desired.

3. Click OK to close this window.

4. Connect a high-precision, external flow meter to the Gas 1 port along with Nitrogen.

5. Select Tools/Instrument Preferences/MFC Page, then select Nitrogen as the Gas 1 purge gas.

6. Access the Notes Page for the "scheduled" run and select #1 Nitrogen from the drop-down list for the Sample. Click Apply.

7. Enter the Sample Flow Rate as 10.0 mL/min and click Apply.

8. Observe the measured flow rate on the external flow meter. Wait until the flow rate stabilizes and record this value.

9. Repeat steps 7 and 8 until all of the calibration values are obtained, changing the flow value the Sample Flow Rate. (Typical calibration flow rates are 10, 50, 100, 150, and 190 mL/min.)

10. Select Calibrate/Mass Flow Controller. Click on the Nitrogen Table tab.

11. Enter the Requested Flow and Measured Flow calibration values obtained. Click OK.

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Calibrating the MFC Helium Tables

This table is used to enter the calibration values for helium.

1. Select Calibrate/Mass Flow Controller. Click on the Helium Table tab.

2. Click the Reset button to set the observed values to zeroes. The Requested Flow and Measured Flow values will display the recommended flow rates for calibration. These values may be changed, if desired.

3. Click OK to close this window.

4. Connect a high-precision, external flow meter to the Gas 1 port along with Helium.

5. Select Tools/Instrument Preferences/MFC Page, then select Helium as the Gas 1 purge gas.

6. Access the Notes Page for the "scheduled" run and select #1 Helium from the drop-down list for the Sample. Click Apply.

7. Enter the Sample Flow Rate as 10.0 mL/min and click Apply.

8. Observe the measured flow rate on the external flow meter. Wait until the flow rate stabilizes and record this value.

9. Repeat steps 7 and 8 until all of the calibration values are obtained, changing the flow value for the Sample Flow Rate. (Typical calibration flow rates are 10, 50, 100, 150, and 190 mL/min.)

10. Select Calibrate/Mass Flow Controller. Click on the Helium Table tab.

11. Enter the Requested Flow and Measured Flow calibration values obtained. Click OK.

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