Vaisala SHM40 - Manual (Page 54)

USER'S GUIDE____________________________________________________________________
52 __________________________________________________________________ M211423EN-B
1. Press the Menu button and select the
Calibration submenu.
2. Select the quantity to be calibrated at menu
item [1] Quantity. You can calibrate
Temperature (T) or Relative Humidity (RH)
measurement. All other humidity quantities
are calculated from RH and T, so they will
also be adjusted.
3. Select the number of calibration points at
menu item [2] Points. You can perform a
1-point or 2-point calibration.
For 2-point calibration, you need two
reference environments. For example, LiCl
and NaCl salt chambers provide 11 %RH and
75 %RH references.
4. Place the probe in the first reference
environment (first calibration point). Wait
20 – 40 minutes for the reading to stabilize.
5. Select menu item [3] Point 1 and press the
Set button. The HM40 now shows the
currently measured value of the selected
quantity. Set the reference value using the
arrow buttons and press the OK button.
The correction to the measurement at point 1
is now shown in the text for menu item [3]. If
you are only doing a 1-point calibration, skip
to step 8.
6. Place the probe in the second reference
environment (second calibration point). Wait
20 – 40 minutes for the reading to stabilize.