声速测量实验装置设计与实现  

The design and realization of sound velocity measurement device

作　　者：侯林涛[1] 陈美銮[1] 翟志雄[1] 

机构地区：[1]暨南大学理工学院物理系

出　　处：《实验技术与管理》2009年第5期62-65,共4页Experimental Technology and Management

基　　金：广东省自然科学基金(8451063201000074);暨南大学博士启动基金(51207037);暨南大学青年基金(51208031)

摘　　要：研制了一种声频率范围内的声速测量系统。该系统主要包括单片机模块、DDS信号发生模块、滤波放大模块及声波导管模块。该装置能控制DDS输出不同频率的正弦波，正弦波信号通过滤波放大电路驱动扬声器发声，声音在声波导管中传播，当改变扬声器与传声器的距离时，合成声波的幅值与相位将发生一系列有规则的变化，并形成驻波，最后由传声器拾取并送示波器显示。可用驻波极值法与相位比较法对声波的波速进行测量，在听觉和视觉上效果明显，可作为普通物理实验装置，也可作为物理演示仪器。The paper presents a new type of audible sound velocity measurement system. The system can be separated into four units, which are the single chip module, the DDS （Direct Digital Synthesis） signal generator module, the filter and amplifier module and the wave guide pipe module. The DDS module generates sine wave signal of varied frequencies, which enables the loudspeaker to generate a sound through the filter and am- plifier module. The sound transmits in the wave-guide tube, with its amplitude and phase experiencing a series of changes, and is received by the microphone. In the last, all wave signals are displayed on the oscilloscope. The sound velocity can be measured by using two methods： the phase comparison method and the resonant in- terference method. This sound velocity measurement system exhibits excellent performances in both vision and audition and can be used in general physics experiments or demonstrating physics experiments.

关 键 词：声速测量 单片机控制 DDS信号发生器 

分 类 号：O4-33[理学—物理] G642.423[文化科学—高等教育学]