1-point adjustment of RH measurement using MI70 indicator (HMP110 and HMP113) - HMP110 - HMP113 - HMP60 - HMP63 - MI70

HMP60 and HMP110 Series User Guide

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If you want to perform a 2-point adjustment instead of a 1-point adjustment, use Vaisala Insight software or the serial line. See Vaisala Insight software and 2-point adjustment of RH measurement (HMP110 and HMP113).

To perform a 1-point adjustment to the capacitance measurement of the HMP110 or HMP113 using the MI70 indicator, you need:

  • MI70 indicator
  • Connection cable for MI70 indicator (Vaisala item code 219980)
  • One humidity reference. 1-point adjustment with a single < 50 %RH reference will adjust the offset parameter of the measurement. 1-point adjustment with a single > 50 %RH reference will adjust the gain parameter of the measurement.

The following procedure uses the HMK15 Humidity Calibrator. LiCl salt (11.3 %RH at 25 °C) is used as the reference point.

For more information on using a humidity calibrator and salt chamber references, see Vaisala Humidity Calibrator HMK15 User Guide M210185EN.
  1. Connect the probe to Port I of the MI70 indicator.
  2. Turn on the MI70 indicator.
  3. Start the adjustment sequence from Main menu > Functions > Adjustments.
  4. MI70 notifies you that automatic power off is disabled during adjustment mode, press OK to acknowledge.
  5. Select the RH parameter when prompted.
  6. Now the adjustment mode is on, press ADJUST to select the adjustment method.
  7. Select 1-point adjustment, press SELECT. Press OK to continue.
  8. Insert the probe in the LiCl salt chamber of the humidity calibrator (11 %RH).

    You can follow the stabilization from the GRAPH display. Press READY when the reading is stabilized.

  9. Give the reference humidity value by using the arrow buttons. Press OK.
  10. Confirm the adjustment, press YES (by pressing NO you return to adjustment mode display and no changes are made).
  11. Adjustment has been carried out. Press BACK to exit the adjustment mode, and press EXIT to return to the basic display.