SoundAdvisor Model 831C
B-1
Appendix B
Measuring Sound Using IEC 61672-1
B.1 Overview
This appendix presents information for assessing the
sound level meter functionality of the Larson Davis
SoundAdvisor Model 831C according to IEC 61672-1
Edition 2.0 2013-09.
B.2 Section 9.3
a) Reference Sound Pressure Level
The reference sound pressure level is 114 dB re 20 µPa.
b) Reference Level Range
The reference level range is 0 dB gain (SLM) and High
Range (OBA).
c) Microphone Reference Point
The microphone reference point is the center of the
diaphragm of the 377B02 microphone.
d) Periodic Testing
Table A.7, “SLM with PRM831 and 377B02 Microphone,”
on page 10-A lists values of 831C with PRM831 and
377B02 Microphone adjustment data of A-weighted
levels used for periodic measurements.
e) Frequency Response and Corrections
See Table A.7, “SLM with PRM831 and 377B02
Table B.1 831C with PRM831 and 377B02 Microphone average frequency responses and
corrections Required by IEC 61672-1
Exact
Frequency
0° Free Field
Response
0° Free Field
Corrections
1
Effect of
Wind Screen
Wind Screen
on 831C 0°
Free Field
0° Free Field
Corrections
with Wind
Screen on
831C¹
expanded
uncertainty
of
Corrections
'@ 95%
Hz
dB
dB
dB
dB
dB
dB
251.19
-0.03
0.03
0.03
0.00
0.00
0.25
316.23
-0.11
0.11
0.15
0.04
-0.04
0.25
398.11
0.12
-0.12
-0.03
0.09
-0.09
0.25
501.19
0.14
-0.14
0.00
0.14
-0.14
0.25
630.96
0.18
-0.18
-0.09
0.09
-0.09
0.25
794.33
0.15
-0.15
-0.07
0.08
-0.08
0.25
1000.00
0.00
0.00
0.00
0.00
0.00
0.25
1059.25
0.00
-0.00
0.11
0.11
-0.11
0.25
1122.02
-0.12
0.12
0.03
-0.09
0.09
0.25
1188.50
-0.21
0.21
0.13
-0.08
0.08
0.25
1258.93
-0.39
0.39
0.31
-0.08
0.08
0.25
1333.52
-0.29
0.29
0.21
-0.08
0.08
0.25
1412.54
-0.27
0.27
0.20
-0.07
0.07
0.25
1496.24
-0.13
0.13
0.07
-0.06
0.06
0.25
1584.89
-0.02
0.02
0.23
0.21
-0.21
0.25
