混响室法测量吸声系数的不确定度评价

Uncertainty Evaluation for the Measurement of Sound Absorbing Coefficient in Reverberation Room

通过对材料吸声系数混响室法测量分析,确定了该类方法测量结果不确定度的来源。对不确定度构成分量进一步分析,结果表明吸声系数的测量不确定度主要由混响时间测量的不确定度所决定,混响室体积、试件尺寸和声速测量的不确定度对吸声系数测量结果的不确定度贡献很小。混响时间测量结果的不确定度主要取决于混响室声场扩散程度,而测量装置本身引入的不确定度贡献较小。

Based on the measurement of sound absorption coefficient in reverberation room, the source of the uncertainty of measurement result is identified. Uncertainty components are further analyzed, results showed that the measurement uncertainty of absorption coefficient is mainly introduced by measurement of reverberation time, the volume of reverberation room, size of specimen and velocity of sound measurement have little contribution to the uncertainty of sound absorption coefficient measurement. The uncertainty of reverberation time measurement depends on the diffusion degree of room sound field , the contribution of measuring device is small.