Larson Davis 831, User Manual

Page: 68 / 548

Model 831 Manual Setup Tabs 4-13
Basic Exceedance Event Data
Note that hysteresis is only utilized
to define the conclusion of a noise
event for basic event counting as
described in this section. It is not
used in conjunction with the
acquisition of noise event history
data. The following exceedance event data are provided for each
of the five threshold levels:
• The number of exceedances of each threshold level.
• The sum total of the time the measured level was
exceeded the threshold level.
Noise Event History Data
When the Model 831 has the optional 831-ELA firmware
loaded, detailed sound level data associated with exceedance
events are measured and stored. For details, see Chapter 13
"Event History” on page 13-1
Sound Recording of Exceedances
If the optional 831-SR firmware has been enabled, automatic
sound recordings of each exceedance can be made. See
“Event Sound Recording” on page 16-14.
Day/Night Tab
Note that the default values for these
parameters are as shown in
FIGURE 4-12. Among the parameters measured and displayed as part of a
basic sound level measurement are the community noise
descriptors L
DN
and L
DEN
. The Day/Night tab is used to
define the times and penalties to be used.
FIGURE 4-12 Day/Evening/Night Definition