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National Standard of the People's Republic of China
Acoustical levels and refrence quantitics
Acoustical levels and refrence quantitics This standard gives the definition and reference values of acoustic quantities when they are expressed in levels. 1 Terminology
1.1 Acoustic levels
UDC534.44
G83238-82
In acoustics, the level of an acoustic quantity is the logarithm of the ratio of the quantity to the reference value of the same type of quantity. The base of the logarithm, the reference value and the category of the level should be mentioned.
Note: The category of the level is indicated by a name. For example, the voltage level, the power level, etc. The unit of measurement of the level is the logarithm of the reference ratio of the same logarithmic conditions, that is, g,. When "-u", this unit is called × bel. ③ The definition of the acoustic level is:
L-=loR, (r/x,)
Where: L is the level of an acoustic wave;
r is the base of the logarithm;
——a certain sound level!
The legal value of high-level acoustic noise.
1.2 Bel and decibel
Beiel is a unit of magnitude with a logarithm base of 10, symbolized by B. Bel is only used in comparison with power. Decibel is one tenth of a bel, and its symbol is dB. Decibel itself is also a unit of sound level, which is a unit of sound level with the 10th root of 10 as the logarithmic base, and decibel is only used for quantities that are analogous to power. Note: () The quantities that are analogous to power are power, sound intensity, sound energy density, power density, time squared, vibration potential, force squared, etc. When using sound, it is actually medium pressure level, "generally referred to as pressure sensitive, which is absolutely the same. ② The decibel value of sound power level and sound pressure level is; W - 10log(W/W)
L, = 20log(p/ p)
W. In Chinese: W, - power and sound pressure,
Wo, po is the reference level of sound power and sound pressure. 2 Levels of commonly used acoustic quantities and their reference values
The levels of commonly used acoustic quantities and their reference values are listed in Table 1. The reference values of other acoustic quantities such as pressure spectrum level, sound level, noise level, etc. can be determined based on the definition of the quantity and the reference values of the relevant quantities listed in Table 1. 3 Representation of levels of acoustic quantities
In order to avoid misunderstanding, when an acoustic quantity is expressed in levels, its reference value should also be stated. For example, Lr = 80dB (0dB 20μ Pa)
The sound pressure represented by this pressure level is 80dB (104 times) higher than the reference value of 20μPa, that is, 0.2Pa. Issued by the National Bureau of Standards on June 8, 1982
Implemented on July 1, 1983
Acoustic level
Acoustic power level
State intensity level
Acoustic energy density level
[Vibration] displacement level
[Reporting] velocity level
[Vibration] added inversion level
Energy level
White field [Voltage sensitivity (level)]
Additional notes:
GB3238--82
Levels of commonly used sound quantities and their reference values
Lp - 20log(p/pa)
Lw - 10log(w/w)
1. =10iog(1/fo)bZxz.net
1-, - 10log(D: Dt)
Ld = 20lug(d/d,)
Iu = 20log(u/u,)
La 201og(a/u,)
Lr= 20logtF/Fr)
L:- 10logtF/Er)
M -201og(M/Mi)
This standard is approved by the National Technical Committee for Acoustics Standardization. National Technical Committee for Acoustics Standardization
Chairman: Ma Daxian, Vice-chairman: Bo, Wu Dasheng, Xu Weiyi. This standard is proposed by the Subcommittee on Basic Acoustics. South China Basic Science Subcommittee
In air: pe=2nμPa
In water: p-iμPa
Wr-ipw
I=IpW/m2
h=IpJ/m
d. =lpm
U,= lnm/s
Qg=1μm/s2
F,=1μN
In air: M. ={V/Pa
In water: M,=IV/μPa
Chairman: Daxian, Chairman: Wu Wenyi. Members: Wei Rongjue, Du Lianyao, Guan Dinghua, Li Peizi, Zhang Suola, Yang Jingang, Gu Zhi, Li Lin, Liu Dongsheng, Jiang Xuehua, Chen Xiancai. Zhang Ruwei.
This standard was drafted by the "Academic Terminology" and other standard compilation groups. Team leader: Ma Daxian, team members (in alphabetical order): Yu Chao, Pin Ruyu, Bei Xi, Wang Chenghao, Li Zhen, Yang Jingang, Zha Jixuan, Xu Weiyi, Qian Zuwen, Zhang Zhuangwei.
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