Vaisala HMK15 - Manual (Page 26)

User's Guide ________________________________________________________
24 _____________________________________________________M210185EN-C
- Take off the grid or filter protecting the sensor. Take care
not to damage the sensor.
- Some 12 mm probes need a adapter fitting to fit into the
13.5 mm hole. Adapter fitting prevents sensor from
soaking in the salt liquid. In case you need an adapter
fitting, take off the grid or filter and replace it with the
adapter fitting. Two adapter fittings are attached on the
base plate of the HMK15, see Figure 1 on page 8.
CAUTION Remember to check from the user's guide of your device if
the adapter fitting is needed. If sensor accidently soaks in
salt liquid, remove it quickly and rinse with clean water.
Let it dry before taking into use again.
- Insert the probe into a suitable hole of the LiCl salt
chamber. Press it downwards until it passes the O-rings.
The shorter the time the hole stays open before inserting
the probe, the shorter the stabilization time required.
- Wait until the humidity reading stabilizes; this takes
about 10 … 30 minutes.
- Read the salt chamber temperature from the thermometer
and then read the closest humidity value from the
calibration table (Greenspan's Calibration Table on page
25, LiCl solution).
- Adjust the dry end (DRY, offset) to correspond to the
value given in the calibration table.
- Insert the thermometer into the 13.5 mm hole of the NaCl
salt chamber.
NOTE When calibrating probes that are being used for long term
measurements (over 1 hour) in high humidities
(90 … 100 %RH), use the K
2
SO
4
salt as the high end
reference.