ISO 7196 pdf download

ISO 7196 pdf download.Acoustics – Frequency-weighting characteristic for infrasound measurements 1 Scope This In4emtioml Standard specifies a frequency- weighting cha~ad-tjc, designated G. for the deter- rniriardion OB weighted sound pressure levels of sound or noise wkme spemurn hex+ port& or wholly within the frequency bard tiram: t Ht ta 2Ci Hz. 1′ In; the w e af wideband noises whose spectrum em- braces- both, the infiramnic and audio-frequency ranges, use of, this International. Standard to determine the infrasonic w e i g h t sound’ pesure level is supplementary to the de- scription of sime noise by methods already standard- ized which cover the audio-frequency range only, for example the descriptkm in terms of A-weighted sound pressure level. The numerical value of the results will, in general, differ from the G-weighted result. No significance should be attached to this difference. since the respective results relate to different parts of The noise spectrum with little overlap. 2 The G-weighting can also be used in connection with the determination of sound power levels and sound intensity levels. When measured with the G-curve, these are sym- bolized respectively as kG and L,G. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate: the possibility of applying the most re- cent edition of the standard indicated below. Mem- b s of IEC and I S0 maintain registers of currently valid International Standards. I EC 651 :I 979, Sound level meters. 3 Definitions For the purposes of this International Standard, the following definitions apply. 3.1 infrasound: Sound or noise whose frequency spectrum lies mainly in the band from 1 Hz to 20 Hz. 3.2 audio-frequency sound: Sound or noise whose frequency spectrum lies mainly in the band from 20 Hz to 20 O00 Hz. 4 Specification of frequency-weighting characteristic G The G frequency response is obtained with a combi- nation of poles and zeros in the complex frequency plane, as given in table 1 . The relative frequency re- sponse corresponding to this pole-zero configuration is given in table2 and shown graphically in figure 1. The G-weighting curve is so defined that it has a gain of O dB at 1 0 Hz, that is,...