Sometimes we need to monitor noise levels on an ongoing level and make longer measurements sub-divided by shorter measurement durations such as 5 minutes, 15 minutes or 1 hour.
According to error analysis of sound levelmeasurement and practical case some objection was raised to levy standard on Noise Exceeding Environment standard.
依据声级测量的误差分析，结合实例，对国家现行《超标环境噪声排污费征收标准》提出异议。
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At last, correction method of low level signal measurement is discussed duo to effect of spectrum analyzer floor noise.