Larson Davis 831C-FFT, Справочное руководство

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SoundAdvisor Model 831C A-20
A.4.2 OBA Measurement System Details
Integration Method
: Follows setting for SLM
Frequency Weightings : Independent of setting for SLM, selected frequency
weighting (A, C or Z), indicated by

Time Weightings/Detectors : Follows setting for SLM, time weighting (S, F or I),
indicated by

OBA Measurements
Instantaneous “Live” Metrics : For display and profile graph only. Not stored with
measurement.
Percentile Spectrum Levels , uses same percentages n1 through n6 selected in
SLM, 0.01 to 99.99%.
Table A.17 Table A.12 Octave Band Analysis 1/3 Octave Linearity Range (Continued)
Nominal
Frequency
(Hz)
High OBA Range Normal OBA Range
Nominal
Frequency
(Hz)
High OBA Range
Normal OBA
Range
0 dB
Gain (dB)
+20 dB
Gain (dB)
0 dB
Gain
(µdB)
+20 dB
Gain
(dB)
0 dB
Gain (dB)
+20 dB
Gain
(µdB)
0 dB
Gain
(µdB)
+20 dB
Gain
(µdB)
PR
M
83
1
2500 ≥ 110
30 to 140
≥ 108
12 to 120
≥ 100
10 to 110
≥ 84
6 to 90
Dir
ec
t In
pu
t
2500 ≥ 110
31 to 140
≥ 109
11 to 120
≥ 101
9 to 110
≥ 89
1 to 90
3150 ≥ 109
31 to 140
≥ 107
13 to 120
≥ 99
11 to 110
≥ 84
6 to 90
3150 ≥ 109
32 to 140
≥ 108
12 to 120
≥ 100
10 to
≥ 89
2 to 90
4000 ≥ 108
32 to 140
≥ 106
14 to 120
≥ 98
12 to 110
≥ 83
7 to 90
4000 ≥ 108
33 to 140
≥ 107
13 to 120
≥ 99
11 to
≥ 88
3 to 90
5000 ≥ 107
34 to 140
≥ 105
15 to 120
≥ 97
13 to 110
≥ 82
8 to 90
5000 ≥ 107
34 to 140
≥ 106
14 to 120
≥ 98
12 to
≥ 87
4 to 90
6300 ≥ 106
35 to 140
≥ 104
16 to 120
≥ 96
14 to 110
≥ 82
9 to 90
6300 ≥ 106
35 to 140
≥ 105
15 to 120
≥ 97
13 to
≥ 86
5 to 90
8000 ≥ 105
36 to 140
≥ 103
17 to 120
≥ 95
15 to 110
≥ 81
9 to 90
8000 ≥ 105
36 to 140
≥ 104
16 to 120
≥ 96
14 to
≥ 85
5 to 90
10000 ≥ 104
37 to 140
≥ 102
18 to 120
≥ 94
16 to 110
≥ 80
10 to 90
10000 ≥ 104
36 to 140
≥ 103
17 to 120
≥ 95
15 to
≥ 84
6 to 90
12500 ≥ 103
38 to 140
≥ 101
19 to 120
≥ 93
17 to 110
≥ 79
11 to 90
12500 ≥ 103
37 to 140
≥ 102
87 to 120
≥ 94
16 to
≥ 83
7 to 90
16000 ≥ 101
39 to 140
≥ 100
20 to 120
≥ 92
18 to 110
≥ 78
12 to 90
16000 ≥ 101
39 to 140
≥ 101
19 to 120
≥ 93
17 to
≥ 82
9 to 90
20000 ≥ 100
40 to 140
≥ 99
21 to 120
≥ 91
19 to 110
≥ 77
13 to 90
20000 ≥ 100
40 to 140
≥ 100
20 to 120
≥ 92
18 to
≥ 81
10 to 90
Linear Exponential Units
OBA Live
Equivalent
Level
Spectrum, 1s
L
ω
eq(f)
L
ω 
eq(f)
dB