Larson Davis 831 - Page 498

Model 831 Manual Frequency Response A-61
FIGURE A-36 Certificate of Conformance; PRM831
Preamplifier Model: PRM831 Serial Number: 10123
Certificate of Electrical Conformance
Frequency response of this model PRM831 preamplifier was tested at a level of 1 Vrms with 12pF microphone
capacitance and driving a short cable. Output level at 1kHz is 0.9878 Vrms (-0.107 dBV), uncertainty 0.033 dB.
Results are displayed relative to the level at 1kHz.
0.5
Level
(dB)
0.0
-0.5
-1.0
-1.5
-2.0
2.5 5 10 20 50 100 200 501 1000 1995 5012 10000 19953 50000 100000
Frequency (Hz)
Freq (Hz) Measured (dB) Uncert (dB) Tolerance (dB)
--------- ------------- ----------- --------------
2.51 -1.05 0.075 -0.82, -1.26
3.16 -0.70 0.058 -0.54, -0.86
3.98 -0.46 0.058 -0.34, -0.58
5.01 -0.30 0.036 -0.21, -0.39
6.31 -0.20 0.036 -0.12, -0.26
7.94 -0.13 0.036 -0.07, -0.19
10.00 -0.09 0.016 -0.03, -0.15
12.59 -0.06 0.016 -0.01, -0.11
15.85 -0.04 0.016 +0.01, -0.09
19.95 -0.03 0.016 +0.02, -0.08
25.12 -0.03 0.016 +0.02, -0.08
31.62 -0.02 0.016 +0.03, -0.07
39.81 -0.02 0.016 +0.03, -0.07
50.12 -0.02 0.016 +0.04, -0.06
63.10 -0.01 0.016 +0.04, -0.06
79.43 -0.01 0.016 +0.04, -0.06
100.00 -0.01 0.016 +0.04, -0.06
125.89 -0.01 0.016 +0.04, -0.06
158.49 -0.01 0.016 +0.05, -0.05
199.53 -0.01 0.016 +0.05, -0.05
251.19 -0.01 0.016 +0.05, -0.05
316.23 -0.01 0.016 +0.05, -0.05
398.11 -0.00 0.016 +0.05, -0.05
501.19 -0.00 0.016 +0.05, -0.05
Freq (Hz) Measured (dB) Uncert (dB) Tolerance (dB)
--------- ------------- ----------- --------------
630.96 -0.00 0.016 +0.05, -0.05
794.33 -0.00 0.016 +0.05, -0.05
1000.00 0.00 0.016 +0.05, -0.05
1258.90 0.00 0.016 +0.05, -0.05
1584.90 0.00 0.016 +0.05, -0.05
1995.30 0.00 0.016 +0.05, -0.05
2511.90 0.00 0.016 +0.05, -0.05
3162.30 0.00 0.016 +0.05, -0.05
3981.10 0.01 0.016 +0.05, -0.05
5011.90 0.00 0.016 +0.05, -0.05
6309.60 0.00 0.016 +0.05, -0.05
7943.30 0.00 0.016 +0.05, -0.05
10000.00 0.01 0.016 +0.05, -0.05
12589.00 0.01 0.016 +0.05, -0.05
15849.00 0.01 0.016 +0.05, -0.05
19953.00 0.01 0.016 +0.05, -0.05
25250.00 0.01 0.022 +0.05, -0.05
31500.00 0.01 0.022 +0.05, -0.05
39750.00 0.01 0.022 +0.05, -0.05
50000.00 0.01 0.022 +0.06, -0.06
63000.00 0.00 0.047 +0.07, -0.07
79500.00 0.00 0.047 +0.08, -0.08
100000.00 0.00 0.047 +0.09, -0.09
126000.00 0.00 0.063 +0.10, -0.10
Noise floor data: 1kHz (1/3 Octave) = 0.42 uV, -7.6 dBuV, uncertainty = 0.47 dB
Flat (20Hz-20kHz) = 4.3 uV, 12.6 dBuV, uncertainty = 0.47 dB
Awt = 1.8 uV, 4.9 dBuV, uncertainty = 0.46 dB
Uncertainties are given as expanded uncertainty at ~95% confidence interval (k = 2).
Technician: Leroy Harbaugh Test Date: 10OCT2007