声学.使用声音压力测定噪音源声功率级与声能级.供混响环境原地使用的工程/测定方法

[中文适用范围]： 本国际标准规定了通过将安装在混响环境中的噪声源（机械或设备）发出的测量声压级与来自校准参考的声压级进行比较来确定噪声源的声功率级或声能级的方法。 声源。 使用这些测量值可以计算噪声源在宽度为 1 个倍频程的频带中产生的声功率级（或者，在突发噪声或瞬态噪声发射的情况下，声能级）。 应用频率 A 计权的声功率级或声能级是使用倍频程级计算的。 [外文原描述]： ISO 3747:2010 specifies a method for determining the sound power level or sound energy level of a noise source by comparing measured sound pressure levels emitted by a noise source (machinery or equipment) mounted in situ in a reverberant environment, with those from a calibrated reference sound source. The sound power level (or, in the case of noise bursts or transient noise emission, the sound energy level) produced by the noise source, in frequency bands of width one octave, is calculated using those measurements. The sound power level or sound energy level with frequency A-weighting applied is calculated using the octave-band levels. The method specified in ISO 3747:2010 is suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001. The method is primarily applicable to sources which emit broad-band noise. It can, however, also be used for sources which emit narrow-band noise or discrete tones, although there is a possiblity that the measurement reproducibility is then degraded. The noise source under test can be a device, machine, component or sub-assembly, especially one which is non-movable. The test environment that is applicable for measurements made in accordance with ISO 3747:2010 is a room where the sound pressure level at the microphone positions depends mainly on reflections from the room surfaces. In measurements of ISO 12001:1996, accuracy grade 2 (engineering grade), background noise in the test environment is low compared to that of the noise source or reference sound source. Information is given on the uncertainty of the sound power levels and sound energy levels determined in accordance with ISO 3747:2010, for measurements made in octave bands and for A-weighted frequency calculations performed on them. The reproducibility conforms with that of either ISO 12001:1996, accuracy grade 2 (engineering grade) or ISO 12001:1996, accuracy grade 3 (survey grade), depending on the extent to which the requirements concerning the test environment are met.