7-6
Setting and Viewing Advanced Functions
Model 820 Technical Reference Manual
Step 3
Press the
d
to item 74,
Intv Threshold.
You may
find 80 dB preset but you may enter another value:
(0-255)
This sets the TWA threshold for the
interval time history. For hearing
conservation purposes, 80 dB is
recommended. For most commu-
nity noise purposes, set this
parameter to 0 or slightly above
the noise floor.
Step 4
Press the
d
to item 75,
Intv Period.
Press
m
and the numeric values for the interval period
desired, and then press
e
:
(hh:mm)
This sets the period for the interval
history. (A 1 second Interval may
be selected by entering 00:00)
Step 5
Press the
d
to
Intv Time Sync
, item 76 for these
choices:
[Yes, No]
The Model 820 allows synchroniz-
ing the interval report with the
Daily History Report. If (Yes) is
entered, the Interval Report will be
started (or restarted if already run-
ning) at the start of each hour. For
this to work properly the Interval
Time should be one hour or some
multiples of hours. The benefit of
synchronizing the hourly levels
and the interval reports is that all
the statistics (L
max
, L
n
, etc.) are
available for the hourly noise lev-
els that make up the daily report.
Step 6
Press the
d
to item 77,
Intv Save L
n
’s.
The Choices
are:
[Yes, No]
Yes: This option allows the six L
n
s
for the interval report to be stored.
Step 7
Press the
d
to item 79,
Intv Auto Stop.
The choices
are:
[Yes, No]
Yes: This option will cause the
Model 820 to automatically stop at
the end of each interval, allowing
the precise timing of a series of
manual measurements. To start a
new measurement, the
S
key
must be pushed.
No: This mode must be off for all
automated measurements. It is rec-
ommended that Intv Time Sync be