NF S31-140:1995 Electroacoustics. Instruments for measurement of aircraft noise. Performance requirements for systems to measure one-thirs-octave band sound pressure levels in noise certification of transport-category aeroplanes.
1995NF S31-140:1995 Electroacoustics. Instruments for measurement of aircraft noise. Performance requirements for systems to measure one-thirs-octave band sound pressure levels in noise certification of transport-category aeroplanes.