Calibration and adjustment using handheld meter and reference probe - HMS110 - HMW112 - TMI110 - HMS112 - HMD110 - HMW110 - HMD112

HMDW110 with TMI110 User Guide

Document code
M211726EN
Revision
E
Language
English
Product
HMS110
HMW112
TMI110
HMS112
HMD110
HMW110
HMD112
Document type
User guide
  • A fully charged Vaisala MI70 indicator (the measurement display that is included in the HM70 package)
  • A calibrated reference probe that is compatible with the MI70 indicator (for example, HMP75) and its MI70 connection cable, if not integrated with the probe
  • Connection cable for HM70 handheld meter (219980SP)
  • Medium size crosshead screwdriver (Pozidriv).
  1. Insert the reference probe in the same environment as the probe of the HMDW110 series transmitter. You can also perform this procedure in the ambient environment, as long as it is reasonably stable.
  2. Connect the reference probe to port I of the MI70 indicator (the measurement display that is included in the HM70 package).
  3. Prepare the HMDW110 series transmitter for a service port connection.
    1. Open the cover of the HMDW110 series transmitter.
    2. If the terminal block for terminals 5 ... 8 is wired, pull it out.
      This disconnects the transmitter from supply voltage and prevents possible equipment damage that may be caused by ground loops. The locations of the terminal blocks and the service port are shown in HMDW110 series component boards.
    3. If the other terminal block is wired (terminals 1 ... 4), pull it out also.
      This prevents the communication between the transmitter and the Modbus (RS-485) host from interfering with your connection.
  4. Plug in connection cable 219980SP to the service port of the HMDW110 series transmitter, and the other end to port II of the MI70 indicator.
  5. Turn on the MI70 indicator.
  6. Check and adjust the environment settings of the reference probe if prompted by the MI70.
  7. Select Functions > Adjustments (II) from the menu of the MI70, then select Start. Make sure the symbol for port II is shown after the word "Adjustments", as your reference probe may also be adjustable using the MI70.
  8. The adjustment mode starts. Select OK.
  9. Select the parameter for adjustment. You can only adjust relative humidity (RH) or temperature (T). The rest of the parameters are calculated based on RH and T and can only be viewed.
  10. Check and adjust the environment settings of the reference probe if prompted by the MI70.
  11. The adjustment mode now shows the value of the selected parameter from both instruments, and a delta parameter (for example, ΔRH) that shows the difference between the two.

    Wait at least 15 minutes for the measurement to stabilize, and for the value of the delta parameter to stop changing. Stabilization may take a much longer time, depending on factors such as temperature differences and airflow around the sensors.

  12. The difference between the reading should be no greater than the combined measurement uncertainty of the HMDW110 series transmitter and the reference probe.

    Depending on the result, proceed as follows:

    • If the HMDW110 series transmitter is within its accuracy specification, there is no need to proceed with the adjustment. Select Back > Exit to leave the adjustment mode.
    • If adjustment is required, continue with the next step.
  13. Select Adjust > To same as RH (I)
  14. The MI70 will ask Do you really want to adjust?. Select Yes.

    MI70 shows the text Adjustment done and returns to the adjustment mode after a few seconds.

  15. Check the value of the delta parameter to verify that the adjustment has taken effect.
  16. Select Back to return to the parameter selection screen.
  17. Select a new parameter for adjustment and proceed as instructed above, or select Exit to leave the adjustment mode.
  18. Turn off the MI70 indicator and disconnect the connection cable from the service port.
  19. Reconnect the terminal blocks and close the cover.