Larson Davis System 824, Training Manual

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1-4 824Training Manual 4/19/01
Each of these instruments are available from the Setup
menu.
Viewing Instrument IDs
Push the Setup
key to view the instruments (virtual
instruments) in your 824.
Integrating sound level meter - Measures Leq, SEL, Min, Max,
Peak, with all weights (A, C, Flat) and with all detectors (Slow, Fast,
Impulse) simultaneously. Includes a high and low measuring range.
Sound spectrum analyzer
-
This SLM and RTA measures Leq,
SEL, Min, Max, Peak, with all weights (A, C, Flat) and with all detec-
tors (Slow, Fast, Impulse) simultaneously, plus 1/1 and 1/3 octave data
stored in a time history at storage rates as fast as 8 times per second.
Included are Ln data showing six Ln values, a graph of L1 through L99
(broadband) and six spectral Lns.
Logging
-
Measures Leq, SEL TWA, Min, Max, Peak, with all
weights (A, C, Flat) and with all detectors (Slow, Fast, Impulse) simul-
taneously. Includes time history, interval history, exceedance history,
daily history, Ln percentiles, statistical data, exposure, and dual SLM
(current and overall)
.
Real-time analyzer
-
High speed spectral data gathering of up to
400 spectra per second using Autostore function. Spatial averaging of
any number of spectra. Flexible triggering for data acquisition. Per-
forms RT60, RC, NCB, HTL. Exponential and linear detectors.
Fast Fourier Transform
-
400 line FFT with Hanning or Rectangu-
lar window, snapshot data storage, display zoom with a factor of 2, 4,
or 8. Count averaging (1 to 16384), measures THD, and linear units
can be user defined.
Audiometer
-
Audiometer testing for level, frequency, linearity,
THD, pulse, crosstalk, frequency modulation, narrow band, broad-
band, and speech noise.
Tonality analyzer
-
Performs complex tonality calculations required
by DIN 45681. Measures the frequency of a dominant tone (F
T
), the
level of the tone (L
T
), the bandwidth of the tonal group (
∆
F), the level
of the group (L
G
), and difference of the two levels (L
T
- L
G
). SLM
measures L
A
, L
C
, L
Aeq
, L
Ceq
, L
Amax
, L
Cmax
, L
AFTM5
, L
95
, and L
Ceq
-L
Aeq
. A
snapshot history is provided to store and display data from the various
modes.