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.5, “SLM with PRM831 and 377B02
Microphone,” on page 6-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.5, “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
