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随着现代工业技术发展,工业噪声已成为危害工人健康和污染环境的重要因素,日益引起人们广泛注意。因此,国际标准化组织(ISO)1971年提出的噪声容许标准规定:每天工作11小时,容许连续噪声的噪声级为85—90分贝(A)工作时间减半,容许噪声级提高3分贝(A)。正常人耳刚刚能听到最低限度声压是建立统计基础上。规定为基准声压: P_0=2×10~(-5)牛顿/米~2 1000赫芝=0.0002微巴而另一方面,像喷气发动机产生大约63.25牛顿/米~2声压。由此可见,最大和最小声压之比为3.2×10~6这样宽广的范围内用声压绝对值来衡量是极不方便的,因此在实践中人
With the development of modern industrial technology, industrial noise has become an important factor that endangers the health of workers and pollutes the environment, arousing widespread attention. Therefore, the noise tolerance standard proposed by the International Organization for Standardization (ISO) in 1971 provides 11 hours of continuous operation per day, allowing noise levels of 85-90 dB for continuous noise (A) 50% reduction in operating time and 3 dB improvement in noise level (A) . Normal ear just heard the minimum sound pressure is to establish the basis of statistics. Specified as the reference sound pressure: P_0 = 2 × 10 ~ (-5) N / m ~ 2 1000 Hz = 0.0002 mbar On the other hand, a jet engine produces about 63.25 N / m 2 sound pressure. Thus, the maximum and minimum sound pressure ratio of 3.2 × 10 ~ 6 within such a broad range of sound pressure to measure the absolute value is very inconvenient, so in practice people