Larson Davis System 824, Техническое справочное руководство

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9/29/09 System 824 Views 5-25
Current SLM and Overall SLM Views
Current SLM clears and starts over
when the
R
Reset button is pressed
while running. Overall SLM does not
clear during a reset, but continues
accumulating data.
The System 824 contains two independent data buffers that
can accumulate data separately. In essence, the instrument
becomes two sound level meters in one. The data in the
primary buffer is referred to as the “overall” measurement,
while data in the secondary buffer is referred to as the
“current” measurement.
The
u
and
d
arrow keys can be
used to cycle between the Current
SLM, Overall SLM, Exposure, Ln
Centiles, and Stats views.
The Current SLM and Overall SLM Views have five
common displays which can be cycled through using
the
r
and
l
arrow keys. Since these displays are identical they
will be discussed together. These displays are categorized as
follows:
a) SPL
b) Times
c) Min/Max
Daily
History Ldn, CNEL, Leq 24, LPK-I, LPK-II, Ln’s
(if desired), Lmax and Lmin are
calculated daily; and for each hour of the
day the hourly Leq, EXCD Leq and
background Leq. Can also show wind or
tachometer data using external
transducers.
Metrics Measurement readings adjusted for night
and day noise impact differences.
Adjustments are based on standard
nighttime sound penalties criteria (i.e.
LDN, CNEL, etc.) The total exceedance
and background Leq metrics are also
displayed.
PassBy Shows the largest single 10 dB passby
event detected with its Leq, SEL, Lmax,
duration, and occurrence date and time.
Wind / Tach Shows wind or tachometer data.