Vaisala DM70 - Manual (Page 72)

USER'S GUIDE____________________________________________________________________
12. Confirm the adjustment by pressing Yes. If you press No,
the adjustment display returns and no changes are made.
13. Now the adjustment is completed. To exit the adjustment mode,
press Back.
14. To return to the basic display, press Exit.
1) If there is a temperature difference between the generated reference
and the probe temperature, relative humidity must be calculated to
correspond to the temperature of the probe.
Adjusting Dewpoint T
d/f
NOTE For DMP74B/C, the sensor purge must be performed manually one
hour before adjusting the dewpoint.
T
d/f
Adjustment of DM70
For DMP74A, the reference temperature of the dewpoint should be -
40 ˚C ... -60 ˚C (-40 ˚F ... -76 ˚F).
For DMP74B/C, the reference temperature of the dewpoint should be
-57 ˚C ... -67 ˚C (-70.6 ˚F ... -88.6 ˚F).
To adjust the dewpoint, follow the instructions below:
1. Set the probe to the reference condition. Follow the stabilization
from the graphic display by pressing
Graph. The minimum recommended stabilization time for
this critical adjustment is 5 hours.
2. Perform the manual purge if necessary.
3. Press the Calibration button of the probe handle (see number 4
in Figure 1 on page 11) using a tool with a thin, sharp point, for
example, a small screwdriver. The indicator will switch into the
adjustment mode. To confirm calibration, press OK.
4. Select T
d/f
and press Select.
5. To check the environmental settings, press Yes. To go to
calibration directly, press No.
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