传感器原理传感器原理 (40).ppt

Principle of Sensors传感器原理压电式传感器Inductive Sensors 6.5.2 超声波式传感器及其应用Ultrasonic sensor and its application超声波式传感器超声波式传感器超声波式传感器超声波式传感器 Ultrasonic sensor Ultrasonic sensor 分类：分类：分类：分类：压电式、磁致伸缩式和电磁式等，最常用的是压电式超声传感器Classification:Classification:piezoelectric,magnetostrictive and electromagnetic,etc.The most commonly used is piezoelectric ultrasonic sensor 压电式超声传感器结构压电式超声传感器结构压电式超声传感器结构压电式超声传感器结构Piezoelectric ultrasonic sensor structurePiezoelectric ultrasonic sensor structureUltrasonic transmitterUltrasonic receiver超声波式传感器的应用超声波式传感器的应用超声波式传感器的应用超声波式传感器的应用Application of Ultrasonic Sensors Application of Ultrasonic Sensors 分类：分类：分类：分类：透射型、分离式反射型和一体式反射型。Classification:Classification:transmission type,separated reflection type and integrated reflection type.产品通常标有中心谐振频率中心谐振频率，如如:23kHz、40kHz、75kHz、200kHz、400kHzProducts are usually marked with central resonant frequencycentral resonant frequency：，Such as Such as：23kHz、40kHz、75kHz、200kHz、400kHz超声波传感器产品实物Ultrasonic sensor products in kind超声波测厚度超声波测厚度超声波测厚度超声波测厚度Ultrasonic thickness measurement Ultrasonic thickness measurement 超声检测厚度的方法：共振法、干涉法、脉冲回波法等。共振法、干涉法、脉冲回波法等。共振法、干涉法、脉冲回波法等。共振法、干涉法、脉冲回波法等。Ultrasonic thickness detection method:Resonance method,interference method,pulse echo method,etc.Resonance method,interference method,pulse echo method,etc.脉冲回波法检测厚度的原理如图所示：The principle of thickness detection by pulse echo method is shown in the figure:c超声波在试件中的传播速度。c the propagation speed of ultrasonic wave in the specimen.在示波器上可直接读出发射与接收超声波之间的时间间隔t。被测物体的厚度h为：The time interval t between transmitting and receiving ultrasonic waves can be directly read out on the oscilloscope.The thickness h of the measured object is:超声波测液位超声波测液位超声波测液位超声波测液位Ultrasonic liquid level measurement Ultrasonic liquid level measurement 脉冲回波式测量液位的工作原理图脉冲回波式测量液位的工作原理图脉冲回波式测量液位的工作原理图脉冲回波式测量液位的工作原理图Working schematic diagram of pulse echo measurement of liquid levelWorking schematic diagram of pulse echo measurement of liquid level单换能器从发射到接收的时间 t=2h/Ct=2h/C传感器到液面的距离 h=ct/2h=ct/2Single transducer Time from transmission to reception t=2h/Ct=2h/CDistance from sensor to liquid level h=ct/2h=ct/2双换能器经过的路程：2S=ct2S=ct液位高度：Double transducer The distance traveled:2S=ct2S=ctLiquid level height:c-c-超声波在介质中传播速度超声波在介质中传播速度超声波在介质中传播速度超声波在介质中传播速度C-Ultrasonic wave in medium Medium propagation velocityC-Ultrasonic wave in medium Medium propagation velocity