Operator Manual, Dual-Column Cloud Condensation Nuclei Counter (CCN-200)
DOC-0128 Rev F
9 3
© 2017 DROPLET MEASUREMENT TECHNOLOGIES
As noted on the screen itself, these settings should not be altered without contacting DMT first.
T1, T2,
and
T3 Offsets
and
T1, T2,
and
T3 Gains
adjust the read points of T1, T2, and T3. These should
never be adjusted by the user.
%TG
enhances the response time between SS% changes. It causes the bottom temperature zone of
the column to run a certain percentage lower temperature than a linear gradient. For example, if this
percentage is set to 5% and there is a 10° temperature gradient, the bottom temperature zone of
the column will be set at 9.5° (not 10°) hotter than the top temperature zone.
NOTE: the desired temperature gradient will still be displayed in the delta T box. But the actual set
point of T3 will be offset lower by the %TG temperature gradient percentage. The %TG parameter
should never be adjusted by the user
.
Auto SS
is a parameter accessed by the CCN-200 software. It should never be changed.
The
Sealevel Card Installed
indicator is illuminated whenever the Sealevel card is present. This
indicator should be ON if your computer has this card. (Some older computers have four COM ports
on board, and so this additional COM port is not needed.) If the
Sealevel Card Installed
indicator
does not match the actual instrument configuration, the serial stream may have an incorrect baud
rate.
Max Current Level
indicates the alarm threshold for the laser current. If the actual current exceeds
the value entered in this field, the CCN-200 will generate an alarm.
Liquid Supply Pump
indicates whether the CCN-200’s supply pump for the column being displayed
has a 20 or 60 µl displacement capacity per cycle. This parameter is set to match the specifications
of the pump, and should not be changed unless a new pump is installed.
Last Delta T, Default SS,
and
TG Dum
are parameters accessed by the CCN-200 software. They should
never be changed.
P, I, D
, and
Flow Avg #
are used in the PID control loop.
dt (s)
specifies the interval in seconds at
which the PID routine is called. If this parameter is equal or less than zero, the PID routine estimates
the time it was last called using an internal timer.
