Vaisala DM70 - Manual (Page 32)

USER'S GUIDE____________________________________________________________________
The purge is performed automatically if humidity changes
significantly or quickly and if the dewpoint is low enough.
As a default, the automatic sensor purge is turned on automatically in
DM70. It is recommended not to turn it off. The automatic sensor
purge can also be started manually, which is necessary if the purge has
not been performed during the last 24 hours. If the power is
continuously turned on in DM70, or if DM70 has been left in logging
mode (display on or off), the automatic sensor purge will be
performed at set interval (default = 24 hours).
Turning on/off Automatic Sensor Purge
NOTE When the sensor purge is performed on a regular basis, the
measurement will have the best accuracy and fastest response time.
Perform the sensor purge when starting measuring after the probe has
been stored and always at least once every 24 hours.
The automatic sensor purge can be turned on or off as follows:
1. Open the menu by pressing Open.
2. Select Settings and press .
3. Select Measurement settings and press .
4. Select Autom.Purge and press .
5. To turn the automatic sensor purge off, press Off. To
reactivate the automatic sensor purge, press On.
6. To return to the basic display, press Exit.
Changing Automatic Sensor Purge Interval
If there are high chemical concentrations present in the measurement
environment, it may cause some sensor drift. If you experience this
kind of drift, it may be necessary to perform the sensor purge more
often. The purge interval can be varied between 1 ... 48 hours. Note
however, that more frequent sensor purge will reduce battery
operation time.
1. Open the menu by pressing Open.
2. Select Settings and press .
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