Measurement System - Larson Davis SoundAdvisor 831C Reference Manual

Table A.4 SLM with PRM831 and 377B02 Microphone
Frequency
Hz
31.62
63.10
125.89
251.19
501.19
1000.00
1995.26
3981.07
7943.28
12589.25
15848.93
1. add numbers in this column to levels read on the SLM to correct to the 0° Free Field level at frequency
2. From B&K 4266 Calibrator
3. From B&K UA033 EA
4. Corrections at 95% confidence.
EA - Electrostatic Actuator
WS - Windscreen
Note: Data was taken at reference conditions 23° C, 50% RH, 101.3 kPa

Measurement System

Integration Method:
• Equivalent level integration method can be
Linear or Exponential.
• Exponential integrates the output of the
selected time weighting (Slow, Fast or
Impulse)
Integration Time:
• Minimum: 0.1 s
• Maximum, <0.5dB error: > 23 days
Frequency Weightings: A, C, Z parallel and
simultaneous for each Time Weighting, selected
frequency weighting (A, C or Z) indicated by 
Peak Frequency Weightings: A, C, Z parallel,
selected peak frequency weighting (A, C or Z)
indicated by 
Time Weightings/Detectors: Slow, Fast, Impulse,
Linear and Peak simultaneously, selected time
weighting (S, F or I) indicated by 
Peak Rise Time: 30 µs
Measurements
Instantaneous "Live" Metrics
For display and profile graph, not stored with
measurement.
A primary frequency and time weighting is
selected by setting for RMS and Peak level to
SoundAdvisor Model 831C
0° Free Field
0° Free Field
Corrections with
1,2
Corrections
WS
dB re 1 kHz dB re 1 kHz
-0.14 -0.14
-0.11 -0.11
-0.21 -0.21
-0.08 -0.08
-0.22 -0.12
0.00 0.00
-0.05 -0.45
0.76 0.76
2.91 3.21
5.85 6.15
7.74 7.34
0° Free Field
1,3
Corrections
1,2
dB re 1 kHz
-0.09
-0.09
-0.20
-0.09
-0.22
0.00
-0.02
0.78
3.30
6.42
8.46
display, all levels are available in an "Any Level"
matrix.
Time
Weighting
Linear
Slow
Fast
Impulse
Peak
Overall Metrics
A primary frequency and time weighting is
selected by setting for RMS and Peak level to
display, all levels are available in an "Any Level"
matrix.
Time
Weighting
1
Linear
2
Linear
Slow
Maximum
1. Linear integration method selected by user
2. Exponential Integration method selected by user
0° Free Field Expanded
Corrections with uncertainty of
1,3
WS Corrections
dB re 1 kHz
-0.09
-0.09
-0.20
-0.09
-0.12
0.00
-0.42
0.78
3.60
6.72
8.06
A C
L L
Aeq Ceq
L L
AS CS
L L
AF CF
L L
AI CI
L L
Apeak Cpeak
A C
L L
Aeq Ceq
L L
AƬeq CƬeq
L L
ASmin CSmin
1,4
dB
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.35
0.50
0.50
Z Units
L dB
Zeq
L dB
ZS
L dB
ZF
L dB
ZI
L dB
Zpeak
Z Units
L dB
Zeq
L dB
ZƬeq
L dB
ZSmin
A-6