5-6
Model 3090/3090AK Engine Exhaust Particle Sizer
TM
Spectrometer
Minimum Concentration
Similarly, when the values shown in the Concentration Histogram window
are small, it is useful to note the minimum concentration level defined for a
given particle size or channel. The minimum concentration is shown for
each channel in this graph as a yellow line. In the graph in Figure 5-4, this
minimum concentration level is more apparent in a distribution where the
concentration values measured by the instrument are relatively low. Note
that this curve depends on the averaging time displayed
—the longer the
averaging time, the lower the concentration defined by the curve. This is
because the electrometer noise is improved with longer averaging times.
For a reference on the concentration limits see Figure B-4 in
Appendix B
.
Figure 5-4
Concentration Histogram Showing Minimum Concentration
C h a n g e H o w D a t a i s V i e w e d
The data can be viewed in the following ways:
Changing the Time resolution
Changing the Concentration scale
Selecting a Weight (2D histogram)
Selecting the Display units
