Larson Davis System 824, Technical Reference Manual

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1-16 824 Reference Manual 9/29/09
Comments concerning the
Digital Signal Processor
Although the System 824 does have analog Flat, A-weight,
C-weight and 10 Hz high pass filters ahead of the Analog to
Digital Convertor, most of the measurements use digital
weighting filters created by the Digital Signal Processor.
The Digital Signal Processor implements the following in
order to provide measured data for a wide range of
weightings, filters and detectors.
• A, C and Flat broadband filters
• Real-time FFT and 1/1 and 1/3 octave band filters
• Slow, Fast and Leq true RMS detectors
• Impulse and Peak detectors
Accessories and Optional Equipment
The System 824, 824S, 824L and 824A can be purchased
with or without a microphone; they all include the Model
PRM902 microphone preamplifier.
The System 824, 824L and 824A are delivered with the
following
standard accessories (824-ACC Pack):
• Battery pack, NiMH, 3.6 V, 1.2 AH (BAT010)
• Reference Manual (I824.01)
• Serial cable, DB9S to DIN08 (CBL006)
• AC/DC output cable, 1/8" mini phone plug to dual phono
or BNC (CBL042)
• Universal AC power adapter. (90 to 264 Vac, 50 to 60
Hz, 12 volt output) (PSA027)
• Alkaline battery terminal assembly (AM814.06)
Connects
individual alkaline batteries when NiMH battery pack is not
used.
If the System 824 is not being used
for long periods of time (1 month or
more), it is recommended that the
batteries be removed to avoid
damage to the instrument.
NOTE: Two Terminal assemblies are
provided though only one is used. The
second one is a spare. To avoid losing
them, keep them in the accessory kit in
the carrying case provided.