SoundAdvisor Model 831C
C-9
Integration Method
See
, or
L
eq
See
“Energy Equivalent Sound Level (Leq)”
Level (dB)
A descriptor of a measured physical quantity, typically used in sound and vibration measure-
ments. It is attached to the name of the physical quantity to denote that it is a logarithmic mea-
sure of the quantity and not the quantity itself. The word decibel is often added after the number
to express the same thing. When frequency weighting is used the annotation is often expressed as
dB(A) or dB(B).
Linear Integration
The alternative to
for the 831C SLM. This is the default and most com-
monly used integration method for measuring sound. Linear integrates only the energy during a
given period. It does not show a decay slope of a Fast, Slow, or Impulse exponential detector. For
.
Ln Value
The
Ln
value is the sound level that has exceeded n% over the total measurement time. For exam-
ple, if n=90%, a displayed value of 35dB for L90 means that for 90% of the measurement period
the dB level was at or above 35dB. These statistical values are commonly used to describe the
characteristics of non-steady sound such as environmental noise.
To calculate Ln values, the 831C creates an amplitude distribution table over the range 0 to 200
dB, in amplitude increments of 0.1 dB. This data permits the calculation of Ln values for any value
of n in the range 00.01 to 99.99%.
Locate the Ln values on the 831C by going to
Setup Manager
Ln Page
.
Measurement Duration (T)
The time period of measurement. It applies to hearing damage risk and is generally expressed in hours.
Standard: ANSI S12.19
6300
-0.1
-1.9
-2.0
8000
8000
-1.1
-2.9
-3.0
10000
-2.5
-4.3
-4.4
12500
-4.3
-6.1
-6.2
16000
16000
-6.6
-8.4
-8.5
20000
-9.3
-11.1
-11.2
Table C.4 Frequency Filter Response
Center Frequencies,
Hz
Weighting Network Frequency
Response
1/3
Octave
1 Octave A
B
C
Summary of Contents for 831C-FFT
Page 1: ...Larson Davis SoundAdvisor Model 831C Sound Level Meter Reference Manual...
Page 214: ...SoundAdvisor Model 831C A 50 FIGURE A 47 Model 831C with 377C20 Microphone...
Page 215: ...SoundAdvisor Model 831C A 51 FIGURE A 48 Model 831C with 377C20 Microphone...
Page 216: ...SoundAdvisor Model 831C A 52 FIGURE A 49 Model 831C with 377C20 Microphone...
Page 223: ...SoundAdvisor Model 831C A 59 A 10 Declaration of Conformity...
