Vaisala SHM40 - Manual (Page 52)

USER'S GUIDE____________________________________________________________________
50 __________________________________________________________________ M211423EN-B
Changing the Filter
1. Twist the filter counter-clockwise to open it.
2. Turn the filter until it can be removed. Do not touch the sensors
when pulling it away.
3. Install the new filter and tighten it.
1112-006
Figure 20 Changing the Filter
Calibration
The humidity measurement accuracy of the HMP40S probe should be
checked once a year. You can do this yourself using a humidity reference
(for example, the Vaisala Humidity Calibrator HMK15), or send the
probe to a Vaisala Service Center for calibration. See the back cover of
this manual for contact information.
If the calibration shows that the measurement accuracy is no longer
within specification, the probe must be adjusted. If accuracy cannot be
restored with adjustment, the probe must be replaced. All probes that are
ordered from Vaisala are delivered calibrated. See section Spare Parts
and Accessories on page 61.