The sound wave is the object mechanical vibrations condition (or energy) dissemination form. The so-called vibration is refers to material the particle the reciprocating motion which carries on nearby its position of equilibrium. For example, drum surface after rap, it on high and low vibrates, this kind of vibrational state to disseminates in all directions through the air medium, this is a sound wave. The ultrasonic wave is refers to the vibrational frequency to be bigger than above 20KHz, its each second vibration number of times (frequency) very high, has surpassed the person ear sense of hearing upper limit (20000Hz), people sound wave named ultrasonic wave which cannot hear this kind. Supersonic and may Wen Sheng be essentially consistent, their common ground is one kind of mechanical vibrations, usually will disseminate by the longitudinal wave way in the elastic medium, will be one kind of energy dissemination form, its diversity will be the ultrasonic frequency is high, the wave length, will have the good beam in certain distance along the straight line dissemination and the directivity, at present the abdomen supersonic image formation will use the frequency range in 2~5MHz, (will vibrate 1 time for 3~3.5MHz each second is 1Hz,1MHz=106Hz commonly used, namely each second will vibrate 1,000,000 times, but Wen Bo frequency between 16-20000HZ).
Two main parameters about ultrasonic wave:
Two main parameters about ultrasonic wave are: Frequency: F≥20KHz; Power density: p= emissive power (W)/emitting area (cm2); Usually p≥0.3w/cm2; The supersonic wave energy which disseminates in the liquid carries on the clean to the object surface's contamination, its principle available

聲波是物體機械振動狀態(tài)（或能量）的傳播形式。所謂振動是指物質的質點在其平衡位置附近進行的往返運動。譬如，鼓面經敲擊后，它就上下振動，這種振動狀態(tài)通過空氣媒質向四面八方傳播，這便是聲波。 超聲波是指振動頻率大于20KHz以上的,其每秒的振動次數（頻率）甚高，超出了人耳聽覺的上限（20000Hz），人們將這種聽不見的聲波叫做超聲波。超聲和可聞聲本質上是一致的，它們的共同點都是一種機械振動，通常以縱波的方式在彈性介質內會傳播，是一種能量的傳播形式，其不同點是超聲頻率高，波長短，在一定距離內沿直線傳播具有良好的束射性和方向性，目前腹部超聲成象所用的頻率范圍在 2~5MHz之間，常用為3~3.5MHz（每秒振動1次為1Hz，1MHz=106Hz，即每秒振動100萬次，可聞波的頻率在16－20000HZ 之間）。
超聲波的兩個主要參數：
超聲波的兩個主要參數：頻率：F≥20KHz；功率密度：p=發(fā)射功率(W)/發(fā)射面積(cm2)；通常p≥0.3w/cm2；在液體中傳播的超聲波能對物體表面的污物進行清洗，其原理可用“空化”現象來解釋：超聲波振