
109
Annex 4 Corrections of Windscreen in Free Field
Freq. [Hz]
Value [dB]
Freq. [Hz]
Value [dB]
Freq. [Hz]
Value [dB]
*50.119
-0.04
*398.11
0.06
3162.3
0.12
*63.096
0.04
*501.19
0.04
3981.1
-0.24
*79.433
0.06
*630.96
0.06
5011.9
-0.30
*100.00
0.00
*794.33
0.09
6309.6
-0.33
*125.89
0.03
1000.0
0.14
7943.3
-0.66
*158.49
0.02
1258.9
0.24
10000
-0.71
*199.53
0.03
1584.9
0.30
12589
-1.04
*251.19
0.02
1995.3
0.37
15849
-1.37
*316.23
-0.01
2511.9
0.41
*19953
-1.92
Expanded Uncertainties: U=0.15 (k=2) @ <=4kHz, U=0.21 (k=2) @ >4kHz.
Note: the frequency with * is not requirement of standard, refer to IEC 61672-1 for exact frequency.
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
*50.1
187
*63.0
957
*79.4
328
*100.
000
*125.
893
*158.
489
*199.
526
*251.
189
*316.
228
*398.
107
*501.
187
*630.
957
*794.
328
1.0
0000k
1.2
5893k
1.5
8489k
1.9
9526k
2.5
1189k
3.1
6228k
3.9
8107k
5.0
1187k
6.3
0957k
7.9
4328k
10.
0000k
12.
5893k
15.
8489k
*19.9
526k
Corrections of Windscreen in Free Filed
dB
Hz
PCE-428 / 430 / 432