DOC-0128 Rev F
© 2017 DROPLET MEASUREMENT TECHNOLOGIES
6 8
NOTE: If the supersaturation scans involve changing from a high supersaturation where the OPC
temperature is high to a low supersaturation and low OPC temperature, adequate time must be
allowed for the OPC to cool to 2°C above T3 before taking data. Otherwise there will be
undercounting of the activated particles.
12.2.3
Flows Tab
The
Flows
tab contains indicators and controls associated with system flows, as shown in Figure 43
Flow Set (Vccm)
displays the set value for the current total flow. This value is read from the
SS_Settings.ini
file
when the
SS Table
is selected, but can be changed at any time. The recommended
flow range is near 500 volume CC/min (Vccm), although the instrument can process flows from 200-
1000 Vccm.
Valve Set (V)
displays the voltage sent to the proportional valve that regulates the total airflow
through the CCN. Every proportional valve will use a different
Valve Set (V)
to maintain a given flow.
Valve Set (V)
is an indicator that cannot be changed.
Manual Override
switches the manual valve set mode ON/OFF. In manual override mode, the
Valve
Set (V)
will be ignored and a constant voltage,
Valve Set M (V),
will be used.
Valve Set M (V)
controls the voltage supplied to the proportional control valve. This parameter is
only used when the instrument is in manual override mode.
Sample Flow (Vccm)
displays the measured sample flow.
Sheath Flow (Vccm)
displays the measured sheath flow.
Figure 43: Flows Control Tab
Note
:
Flow affects unit SS%. The CCN unit was DMT factory calibrated with a Total Flow set to
500 Vccm, so Total Flow should be approximately this amount.
