3-2
Model 3786 Ultrafine Water-based Condensation Particle Counter
Bar Graph Screen
The Bar Graph screen displays measured particle concentrations
over history. The graph rolls right to left with new data being added
on the right for each update. The vertical scale is in units of the log
of the particle concentration. The scale is automatically updated to
include the highest recorded concentration over the history. Three
decades of particle concentrations are displayed. The horizontal
time scale is determined by the sample reporting time set by the
communications interface. On power-up the sample reporting time
is set to six seconds. The Bar Graph display then updates every six
seconds with new concentration data. The graph contains a total of
120 time points so twelve minutes of concentration will be
displayed.
If the sample reporting time is changed (see the SM command in
the Communications section), the time associated with each
horizontal bar will changed to match the new setting. If the data
collection mode is turned off (SM,0 command), no data will be
available to graph and the Bar Graph screen will not be available
for viewing. The Bar Graph display also allows a convenient means
to monitor data being reported over the communications interface.
Status Screen
The Status screen provides information about the operating
condition of the instrument. The top line of the display provides
information about liquid handing. The usual display is “Liquid --
Normal” indicating that the instrument has water and the drain
reservoir is not full. Other conditions reported on this status line
are covered in the section on Water Handling.
Liquid -- Normal
Optc 75.0 Photo 225
GT 75.0 Abs 983
Sat 12.0 Flow 300
The left column under the liquid status line provides the operating
temperatures of the Optics (Optc), Growth Tube (GT), and the
Saturator (Sat). The temperatures are reported in degrees
Centigrade. The value indicated next to the “Photo” label is the
