Larson Davis 824 - Periodic Testing of A-Weighted Sound Levels

F-4 824 Reference Manual 9/29/09
Periodic Testing of A-Weighted
Sound Levels
The following table presents adjustment data to be used to determine A-weighted sound levels
equivalent to the response to plane sinusoidal sound waves incident from the reference direction
produced by a calibrated multi-frequency sound calibrator and an electostatic actuator.
1
Add numbers in this column to levels read on the 824 to correct the level at a specific frequency
Frequency,
Hz
0 
Free Field Cor-
rections from
B&K4226
Calibrator
1
dB
0

Free Field Correc-
tions with Wnd
Screen from
B&K4226
Calibrator
1
dB
0

Free Field Cor-
rections from
B&K UA0033
Electrostatic
Actuator
1
dB
0

Free Field Cor-
rections with
Wnd Screen
from B&K4226
Calibrator
1
dB
Expanded uncer-
taintly of Correc-
tions @95%
confidence,
dB
31.62 0.1 0.1 0.0 0.0 0.25
63.10 0.1 0.1 0.0 0.0 0.25
125.89 0.1 0.1 0.0 0.0 0.25
251.19 0.1 0.1 0.0 0.0 0.25
501.19 0.0 0.0 -0.1 -0.1 0.25
1000.00 0.0 0.0 0.0 0.0 0.25
1995.26 -0.2 -0.1 -0.1 0.1 0.30
3981.07 1.3 1.3 1.3 1.3 0.35
7943.28 3.1 3.1 3.6 3.7 0.40
12589.25 6.0 6.0 6.4 6.4 0.50
15848.93 8.2 7.9 7.8 7.5 0.60