利用光学方法测量实验室标准传声器的前腔深度  

Measurement of Front Cavity Depth of Laboratory Standard Microphone by Optical Method

作　　者：何龙标[1] 钟波[1] 许欢[1] 牛锋[1] 陈剑林[1] 

机构地区：[1]中国计量科学研究院,北京100013

出　　处：《计量学报》2010年第3期249-253,共5页Acta Metrologica Sinica

摘　　要：实验室标准传声器的前腔深度是耦合腔互易法校准其声压灵敏度的主要不确定度分量之一。为了控制声压灵敏度校准的不确定度，利用光学三坐标自动测量系统，分别通过直测法和块规法测量3只LSIP和3只LS2P传声器的前腔深度。测量结果表明，在传声器外环面放置高精度的块规，较好匹配了传声器与平面波耦合腔进行声学耦合时的物理模型，其前腔深度测量不确定度优于3．0μm（k=2）。对于LSIP传声器20Hz～10kHz频率范围内的声压灵敏度，前腔深度引入的不确定度分量优于0．005dB（k=2）；对于LS2P传声器，20Hz～25kHz频率范围内的不确定度分量优于0．012dB（k=2），能够实现实验室标准传声器声压灵敏度的高精度校准。In the coupler reciprocity calibration system of laboratory standard microphone, the microphone front cavity depth is one of the most important uncertainty sources. To control the uncertainty of sound pressure sensitivity, the front cavity depth of three LS1P microphones and three LS2P microphones are measured by optical three coordinates measuring machine with the direct method and block gage method. The result shows that the latter method matches the coupling model of microphone and plane wave coupler. The standard deviation of the front depth is less than 3.0 μm（ k = 2 ）. For LSiP microphone in the frequency from 20 Hz to 10 kHz, the uncertainty component is less than 0. 005 dB（ k = 2） and for LS2P microphone from 20 Hz to 25 kHz, the uncertainty component is less than 0. 012 dB （k = 2） , which realizes the laboratory standard microphone pressure sensitivity calibration of laboratory standard microphone with high precision.

关 键 词：计量学 实验室标准传声器 前腔深度 耦合腔互易法 

分 类 号：TB95[一般工业技术—计量学]