声学.声压法测定噪声源声功率级.混响室精密法

[中文适用范围]： 本国际标准规定了根据混响试验室中测量的声压级确定噪声源的声功率级或声能级的方法。 噪声源在三分之一倍频程宽度的频带内产生的声功率级（或者，在突发噪声或瞬态噪声发射的情况下，声能级）是使用这些测量值计算的，包括修正以允许测试时和地点的气象条件与参考特性阻抗对应的气象条件之间的任何差异。 给出了确定声功率级和声能级的直接法和比较法的测量和计算程序。 一般来说，感兴趣的频率范围包括三分之一倍频程，中频范围为 100 Hz 至 10 000 Hz。 附件 E 给出了在较低频率的扩展频率范围内应用指定方法的指南。 本国际标准不适用于 10 000 Hz 三分之一倍频程以上的频率范围。 注：对于更高的频率，可以使用 ISO 9295 中指定的方法。 [外文原描述]： ISO 3741:2010 specifies methods for determining the sound power level or sound energy level of a noise source from sound pressure levels measured in a reverberation test room. 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-third-octave, is calculated using those measurements, including corrections to allow for any differences between the meteorological conditions at the time and place of the test and those corresponding to a reference characteristic impedance. Measurement and calculation procedures are given for both a direct method and a comparison method of determining the sound power level and the sound energy level. In general, the frequency range of interest includes the one-third-octave bands with mid-band frequencies from 100 Hz to 10 000 Hz. Guidelines for the application of the specified methods over an extended frequency range in respect to lower frequencies are given in an annex. ISO 3741:2010 is not applicable to frequency ranges above the 10 000 Hz one-third-octave band. The methods specified in ISO 3741:2010 are suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001. The noise source under test can be a device, machine, component or sub-assembly. ISO 3741:2010 is applicable to noise sources with a volume not greater than 2 % of the volume of the reverberation test room. For a source with a volume greater than 2 % of the volume of the test room, it is possible that the achievement of results as defined in ISO 12001:1996, accuracy grade 1 (precision grade) is not feasible. The test rooms that are applicable for measurements made in accordance with ISO 3741:2010 are reverberation test rooms meeting specified requirements. Information is given on the uncertainty of the sound power levels and sound energy levels determined in accordance with ISO 3741:2010, for measurements made in limited bands of frequency and for A-weighted frequency calculations from them. The uncertainty conforms to ISO 12001:1996, accuracy grade 1 (precision grade).