雷达物位计和超声波物位计区别在哪里？这两种的测量原理究竟是什么？雷达物位计和超声波物位计相比各自的优势是什么呢?
What is the difference between radar level meter and ultrasonic level meter? What are the measurement principles of these two methods? What are the advantages of radar level meter and ultrasonic level meter?
我们一般把声波频率超过20kHz的声波称为超声波，超声波是机械波的一种，即是机械振动在弹性介质中的一种传播过程，它的特征是频率高、波长短、绕射现象小，另外方向性好，能够成为射线而定向传播。
We generally call the sound wave whose frequency exceeds 20kHz as ultrasonic wave. Ultrasonic wave is a kind of mechanical wave, that is, a propagation process of mechanical vibration in elastic medium. It is characterized by high frequency, short wavelength, small diffraction phenomenon and good directivity. It can become rays and propagate directionally.
超声波在液体、固体中衰减很小，因而穿透能力强，尤其是在对光不透明的固体中，超声波可穿透几十米的长度，碰到杂质或界面就会有显著的反射，超声波测量物位就是利用了它的这一特征。
The attenuation of ultrasonic wave in liquid and solid is very small, so it has strong penetration ability. Especially in light opaque solid, ultrasonic wave can penetrate tens of meters, and there will be significant reflection when it meets impurities or interface. Ultrasonic level measurement uses this feature.
在超声波检测技术中，不管哪种超声波仪器，都必须把电能转换超声波发射出去，再接收回来变换成电信号，完成这项功能的装置被称为超声波换能器，也称探头。
In ultrasonic testing technology, no matter what kind of ultrasonic instrument, it must convert electric energy into ultrasonic wave, send it out, and then receive it and convert it into electrical signal. The device that completes this function is called ultrasonic transducer, also known as probe.