1-Point Adjustment with a Reference Gas - MI70 - GMP251

GMP251 User Guide

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English (United States)
Document type
User guide
  1. Connect the GMP251 to Port I of the MI70 indicator.
  2. Feed a calibration gas to the GMP251 using the calibration adapter accessory (Vaisala order code: DRW244827SP). If you are using ambient air as the calibration gas, you must have a reference meter in the same environment to verify the CO2 concentration.
  3. Turn on the MI70 indicator.
  4. Start the adjustment sequence from Main menu > Functions > Adjustments.
  5. MI70 notifies you that automatic power off is disabled during adjustment mode, press OK to acknowledge.
  6. Select the CO2 parameter when prompted.
  7. You may be prompted to check the environmental settings of the reference probe before proceeding. Press Yes to check the settings and Exit when you have checked and corrected the settings.
  8. The adjustment mode is now active, and you can see the measured CO2 reading on the screen. To proceed with the adjustment, press Adjust.
  9. Select 1-point adjustment.
  10. You will be prompted if you really want to adjust. Select Yes.
  11. You are now in the 1-point adjustment screen. Allow the measurement to stabilize and press Ready.
  12. Enter the CO2 concentration of the reference gas and press OK.
  13. You will be prompted if you really want to adjust. Select Yes.
  14. If the adjustment is successful, MI70 will show the text Adjustment Done, after which you will return to the adjustment mode. At this point you can press Back and Exit to leave the adjustment mode. The adjustment is now completed.
    If the adjustment cannot be applied, MI70 will show the text Cannot adjust, possibly followed by a text stating the reason. A possible reason for an adjustment failure is attempting to apply a very large correction to the reading.