Vaisala DM500 - Manual (Page 84)

User's Guide ______________________________________________________________________
82 __________________________________________________________________ M210205EN-D
Calibrating DM500 Equipped with a
Pump
If you have the DM500 with a pump, ensure that the sample flow rate
from the humidity generator is sufficient. See the following example:
Humidity
generator Gas flow
> 3 slpm
1 splm
1 splm
DM500
Reference
instrument Open outlet
(with diffusion coil)
Figure 22 Gas Flow Rate from the Humidity Generator
Making an Adjustment
DMP501 needs 4...10 dewpoint reference points within dewpoint
temperature range -80 ºC...+60 ºC for the adjustment. These dewpoint
reference points shall be traceable to appropriate standards. The
dewpoint temperature references shall cover the measurement area in
which the instrument is used.
The adjustment can be done also by using the serial commands.
If you have adjusted the device earlier, you shall clear the previous
adjustments before giving new adjustment data.
1. Open MENU : press .
2. Select ► Settings , press .
3. Select ► Adjustments , press .
4. Select ► Dewpoint adjustments , press .
5. Press CLEAR and YES , OK to clear the old adjustment
data
Connect the reference gas flow to the gas inlet and measure the
readings in 4...10 points. Write down the readings in the different
reference points. Feed the reference points and corresponding readings
to the device to make the adjustment.