Larson Davis System 824, Reference Manual

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2-2 824 Reference Manual 9/12/00
Instrument Definition (ID) Types
SLM&RTA (SSA)
The SSA ID performs simultaneous sound level measure-
ments and real-time spectrum analysis using 1/1 or 1/3
octave bandwidths. The Instrument Type designation
“SSA” represents Sound Spectrum Analyzer. Sound levels
during the measurement period are displayed and can be
stored for later recall. In addition to a live spectrum display,
the System 824 can display an equivalent level (L
eq
) spec-
trum, a minimum bin by bin level (L
min
) spectrum and a
maximum level (L
max
) spectrum, which is the spectrum time
coincident with the maximum value of the sound pressure
level during the measurement period.
A back erase function allows the removal of up to the last 30
seconds (in one second steps) of data when a disruptive
noise occurs.
Instrument Definition (ID)
SLM&RTA (SSA) Logging (LOG) SLM (ISM)
SLM Range (dBA) 80 105 105
Real-time Spectrum
Analysis 1/1 and 1/3 octave
bandwidths No No
Manual Data Storage Yes Yes Yes
Back Erase Yes No Yes
Automatic Data
Logging Time History
Intervals (sound level
and spectral data) Time History
Exceedance Events
Intervals (sound level) No
Major Applications Noise Reduction Sound
Power Noise Monitoring Noise
Workplace Point & Shoot
Law Enforcement
Workplace Noise