Larson Davis SoundAdvisor Reference Manual page 44

For a more in-
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depth discussion of Ln values,
see in the en i
Ln Value
Gl ary.
4.2. About the Exceedances Page Overall Page
FIGURE 4-15 Overall Tab: Exceedances Page
During the exceedance
SoundAdvisor Model 831C
An Ln percentile is a statistical measurement of the level that exceeds
"n" percent of the time. The statistics are based on the level defined by
the current weighting and detector.
The Ln Pe rce ntile s page displays the 6 Ln statistics for the
measurement based on the run time, and the maximum and minimum
sound levels measured. You can customize the threshold level in the
measurement setup prior to or during a measurement. For details on
6.2.2 Customizing Setup Values On the Setup Manager
this, see
Tabs.
The values of Ln are calculated from an amplitude distribution table,
ranging from 0 to 200 dB, in 0.1 dB increments. As a result, it is possible
to calculate Ln values from values of n ranging from 00.01% to 99.99%.
The Exceedances page has 2 L
4-1 shows that each time a trigger level is exceeded during a run, the
counter for that level advances, and it displays in orange or red instead
of white.
An exceedance occurs when the level defined by the current weighting
and de te ctor e xceeds the Trigger Leve l you se t in the me asure ment
setup. For details on this, see
Setup Manager Tabs.
After the exceedance
Understanding the Overall Tab
and 3 L exceedance values. Figure
AS peak
6.2.2 Customizing Setup Values On the
# of exceedances
Time of last exceedance
4-11