Larson Davis System 824, Technical Reference Manual

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2-8 824 Reference Manual 9/29/09
The large numerals represent the SPL measurement taken
with the Slow detector and the A-weighting. In the lower left
is an indication of the Leq value and the elapsed time of the
measurement for which the Leq value is calculated. The
graph being traced across the display is a time history of the
SPL value.
Stop, Pause and Back Erase Functions
While taking a measurement you can stop, pause, and back
erase.
Stopping and Starting
Measurements
To stop the measurement, press the
s
key. Restart by
pressing
s
.
Pausing Measurements To pause the measurement press the
p
PAUSE key. To
continue the measurement press the
p
key a second time.
While paused, the
l
and
r
keys can be used to move a
cursor across the time history and display the SPL and
secondary parameters as measured at any particular time
during the measurement period.
Back Erasing Should an unwanted sound occur during the measurement,
such as a door slam, you can pause the instrument, cursor to
the left with the
l
key to a time prior to the unwanted
event, and press the
p
key once more to recommence the
measurement from that point, erasing the data to the right of
the cursor. This is the
Back Erase feature as indicated on the
display when the
p
key had been initially pressed.
Changing the detector of the displayed SPL value
You can change the parameters being displayed in the View
window while a measurement is in progress without going to
the Setup menu.