Vaisala DPT146 - Manual (Page 58)

User's Guide _______________________________________________________________________
56 ___________________________________________________________________ M211372EN-D
5. Disable the Auto power off function of the MI70 indicator to
prevent the indicator from powering off in the middle of the check.
Check the setting in the Settings - User Interface menu, and
change if necessary.
6. The MI70 can display three parameters at one time. To compare
the readings of the DPT146 and the reference probe, select the desired
parameter from the Display – Quantities and Units menu of the MI70.
Select the same parameter from port I and II, and the delta parameter that
shows the difference between the two. For example, ∆T
d/f
shows the
difference in dewpoint between the two probes.
1108-039
Figure 23 Comparing Dewpoint Readings on MI70
7. After the measurement has stabilized, check the difference between
the readings. It will give you an indication of the approximate drift
of the DPT146 and its need for calibration. The difference between
the readings should be no greater than the combined measurement
uncertainty of the DPT146 and the reference probe.
8. Write down the results and repeat the comparison for each
parameter you want to check.
9. If adjustment is required, contact a Vaisala Service Center or your
local Vaisala representative to have the DPT146 adjusted.
NOTE Some notes on using the MI70 indicator with the DPT146:
- If you disconnect the DPT146 while the MI70 indicator is on,
the quantities measured will remain on the screen, but no
measurement will be shown.
- Temperature measured by the DPT146 is shown as parameter
Ta (not T) in the MI70.
- The messages from the transmitter will appear in English even if
the MI70 has been set to another language.