Vaisala HMK15 - Manual (Page 15)

Chapter 3 _____________________________________Preparing the Salt Solutions
VAISALA _________________________________________________________ 13
Potassium sulphate generates a reference humidity of
approximately 97 %RH. Potassium sulphate is used as the
wet end reference (gain) for probes measuring in
applications with very high humidities (90 … 100 %RH, for
example outdoor and concrete measurements).
Prepare the salt solutions according to the following
instructions. Measure the salts carefully if you do not use
the ready-dosed packages.
1. Take the calibrator out of the box. Open the transit
cover of the chamber. Remove the measurement cover
from the chamber holder and press the transit cover on
the holder (see Figure 2).
0606-165
Figure 2 Press the transit cover on a chamber
holder
2. Pour ion exchanged water into the chamber; the
required amounts are given in the table:
LiCl 12 ml of water
MgCl2 3 ml of water
NaCl 10 ml of water
K2SO4 10 ml of water