Vaisala HMT310 - Manual (Page 74)

User's Guide _______________________________________________________________________
74 ___________________________________________________________________ M210619EN-E
0507-048
Figure 18 Location of Adjustment Button
NOTE With a warmed probe (HMT317) or sensor heating, heating is interrupted
when the adjustment button is pressed. Allow enough time for the probe
to reach ambient temperature and then start the calibration procedure.
Low End Adjustment
1. Remove the transmitter unit from the mounting plate (see
Mounting the Transmitter/Removing the Transmitter Unit on page
22), and press the adjustment button once (see Figure 18 above).
2. Remove the filter from the probe (see instructions on page 65) and
insert the probe into the dry end reference chamber (for example,
LiCl: 11 % RH in the humidity calibrator HMK15, use adapter
fitting 13.5 mm for HMT314, HMT315, HMT317, and HMT318).
3. Wait at least 30 minutes for the sensor to stabilize.
4. Issue the CRH command and press Enter.
5. Type C and press Enter a few times to check if the reading is
stabilized.
6. When the reading is stabilized, type 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.