Larson Davis System 824 - Selecting a Measurement Setup

9/12/00 Overview 2-5
•L
max
, L
min
, SEL, and L
eq
(q=3) or Time Weighted Aver-
age (q=4, 5, or 6) levels for a selected detector (Slow,
Fast, or Impulse) and a selected frequency weighting (A,
C, or Flat)
•L
peak
level corresponding to the frequency weighting
selected for L
eq
(see charts above) and a second L
peak
level corresponding to one of the two alternative choices
of frequency weighting.
•L
n
(6 values with 0.1 dB resolution, based on user-
selected percentages with 0.01% resolution)
• Date, time and duration of interval
• Six user-selected values of L
n
can be measured and
stored as part of the automatic interval data storage func-
tion.
• A special feature is the automatic measurement and log-
ging of data associated with noise exceedance events that
are triggered by the sound level exceeding a user-defined
threshold. L
eq
, SEL and L
Peak
for each event are logged
along with a Time History of the sound level during each
event.
• Daily history and community noise metrics.
Selecting a Measurement Setup
The simplest way to setup the instrument is to select the ID
which most closely meets the requirements of the measure-
ment to be made and then modify it to meet your specific
needs. The instrument is delivered with a number of perma-
nent setups. The standard ID delivered with the instrument is
ISM. The optional IDs available are: SSA, LOG, RTA, FFT,
AUD, and TAL. If the options for the SSA, LOG, RTA, FFT,
AUD, or TAL have not been purchased, they can be evalu-
ated in a
demo mode
.
Restrictions of demo IDs:
• Cannot print reports