BS 7135-2:1989

National foreword
Committees responsible
Method
0 Introduction
1 Scope and field of application
2 References
3 Requirements for measurements in a reverberation
     room
4 Method using measured reverberation time
5 Method using calculated air absorption
6 Method using a reference sound source
7 Method using a free field over a reflecting plane
8 Calculation of A-weighted sound power level
9 Information to be recorded
10 Information to be reported
Annexes
A Coaxial circular paths in parallel planes for
     microphone traverses in a free field over a
     reflecting plane
B Calculation of air absorption coefficient
Tables
1 Air absorption coefficients
2 Values of the A-weighting factor, Aj, for j = 1 to
     24
3 Type of noise and determination of sound power
     levels
Figure
A.1 Circular paths for microphone traverses

Four methods for determining the sound power levels of high-frequency noise in the octave band centred at 16 Hz, three based in the reverberation room technique and on in free-field conditions over a reflecting plane.