Performing two-point humidity and temperature adjustment - HMP155

HMP155 User Guide
Document code
M210912EN
Revision
G.1
Language
English
Product
HMP155
Document type
User guide
  1. Carry out chemical purge, if available.
  2. Uncover the adjustment buttons on the probe by removing the protective cover and the calibration seal.
  3. Open the protective plug.

    There are 3 buttons marked -, □, and +. There is also a 2-colored indicator LED. See Figure 1.

  4. To change HMP155 to the adjustment mode, press the ADJ button and hold it down until the green indicator LED lights up.
    Do not touch the adjustment buttons before the conditions have stabilized.
  5. To perform the low humidity offset adjustment, remove the filter and insert the probe into a measurement hole of the dry end reference chamber (for example, LiCl: 11 %RH).
    Do not touch the adjustment buttons before the conditions have stabilized. This takes approximately 30 minutes.
  6. Using the - and + buttons, make sure the Aout voltage is correct and press the ADJ button. The green indicator LED turns off and back on.
  7. Insert the probe into the high-end reference chamber (for example, NaCl: 75 %RH chamber in the humidity calibrator HMK15) and perform the high humidity gain adjustment by using the - and + buttons to make sure the Aout voltage is correct. To finish the relative humidity calibration and adjustment, press the ADJ button and the red indicator LED lights up.
    If you do not want to perform the temperature adjustment at this time, press the ADJ button twice. The indicator LED turns off. After a reset, HMP155 exits the adjustment mode. Otherwise, continue with the next step.
  8. Insert the probe into a known reference temperature (if HMK15 humidity calibrator is not used) and let the temperature reading stabilize.
    Do not touch the adjustment buttons before the conditions have stabilized.
  9. Using the - and + buttons, make the temperature offset adjustment by making sure the Aout voltage is correct and press the ADJ button. Red indicator LED turns off and back.
    If you do not wish to perform the two-point temperature adjustment now, press the ADJ button one more time so that the red indicator LED turns off. After reset, HMP155 exits the adjustment mode. Otherwise, continue with the next step.
  10. Insert the probe into another reference temperature.
    Do not touch the adjustment buttons before the conditions have stabilized.
  11. Using the - and + buttons, make the temperature gain adjustment by making sure the Aout voltage is correct.
  12. Press the ADJ button one more time so that the red LED turns off to indicate the probe has quit the adjustment mode.
  13. After the procedure, tighten the protective cover properly.

    To avoid water leaking in, make sure that there is no gap.