User`s guide

User’s Guide ______________________________________________________________________
154 __________________________________________________________________M210662EN-A
0406-072
Figure 115 HMH40-MAWS Handle
Leave the calibrator and the probe head in the same space for at least
four hours so that their temperatures have time to equalize. Unscrew the
plastic grid of the probe.
The calibration is done first for the dry end (<50 %RH) and then for the
wet end (>50 %RH) by adjusting the trimmer potentiometers marked
with D (dry) and W (wet). The potentiometers are located under a
protective plug. Use a ceramic with 2.5 mm (0.1 in.) blade for adjusting
the potentiometers.
As the D (dry) and W (wet) adjustments may affect each other, recheck
the humidity reading at the low end. If necessary, repeat the adjustments
in both the low and the high humidity points, until the reading is correct.
NOTE
If zero point is calibrated in nitrogen (N2), the minimum output signal
of 0.008 V corresponds to a relative humidity of 0.8 %RH.
Table 20 Greenspan’s Calibration
Temperature [°C] 15 20 25 30 35
LiCl [%RH]
1
1. Do not use or store the LiCl solution in temperatures below +18 °C (64 °F) as its humidity equilibrium
may change permanently.
11.3 11.3 11.3 11.3
NaCl [%RH] 75.6 75.5 75.3 75.1 74.9
K2SO4 [%RH] 97.9 97.6 97.3 97.0 96.7