Instrument Operation 3-3
current raw photometric reading which is typically between 150
and 280 for when no particle are detected. This value increases
with particle concentration and provides an indication of the
amount of light incident on the photo detector. The label “Abs”
refers to the absolute inlet pressure and is reported in millibar. The
final indicator labeled “Flow” provides the current aerosol flow rate
measured by the instrument in units of cm
3
/minute.
Totalizer
This screen displays a running total of particle counts, elapse time,
and calculated concentration. Operation of the Totalizer is
controlled using the Totalizer button. Pressing the Totalizer button
will start data collection. Once started, the Totalizer accumulates
particle counts and elapsed time. Pressing the button a second time
will stop the counter and the timer, holding the current count, time
totals, and the calculated concentration. Pressing the button a
third time will clear the Totalizer preparing it for a new sample.
Subsequent presses of the Totalizer button will repeat the Run,
Stop and Reset sequence.
2.59 #/cm
3
454 particles
35.0 seconds
The totalizer function is intended for low concentration
measurements and will display “Over” if the concentration exceeds
2000 particles/cm
3
. No live-time correction is used in the
accumulation of time. The Totalizer will stop automatically when
the maximum time of 3600 seconds is reached. Eight digits of
particle counts can be displayed. The displayed concentration
range is from 0.0000 to 1000 particles/cm
3
. The concentration
displayed on this screen differs from the value shown on the
Primary Concentration display because it is calculated solely on
particles counted and elapse time of the totalizer sample.
To Next Page
Loading...
Need help?
General
