Vaisala MMT310 - Manual (Page 57)

Chapter 6 ____________________________________________________ Calibration and adjustment
VAISALA ________________________________________________________________________ 57
Low End Adjustment
1. Remove the transmitter unit from the mounting plate (see page 18),
and press the adjustment button once (see Figure 15 on page 56).
2. Remove the filter from the probe and insert the probe head into a
measurement hole of the dry end reference chamber (for example
LiCl: 11 % RH in the humidity calibrator HMK15, use the adapter
fitting (13.5 mm)).
3. Wait at least 30 minutes for the sensor to stabilize.
4. Issue the CRH command and press ENTER.
Type C and press ENTER a few times to check if the reading is
stabilized.
5. When the reading is stabilized, give the reference humidity after
the question mark and press ENTER.
>crh
RH : 11.25 Ref1 ? c
RH : 11.25 Ref1 ? c
RH : 11.25 Ref1 ? c
RH : 11.24 Ref1 ? c
RH : 11.24 Ref1 ? 11.3
Press any key when ready ...
Now the device is waiting for the high end reference. Carry out the
high end adjustment as instructed in the following section.