Ultrasound has now been widely known and used in many fields. The rise of ultrasound has brought a lot of convenience to people. People's lives have been closely linked with ultrasound. Imagine if humans lost ultrasound, the human world would be What changes.

Ultrasound, English ultrasound. As the name suggests, it is a sound wave whose frequency exceeds the highest threshold (20kHz) that the human ear can hear. The frequency of sound waves that the human ear can hear is 20Hz ~ 20kHz. Sound waves below 20Hz are called infrasounds. The ultrasonic wave has good directivity and strong reflection ability, and it is easy to obtain concentrated sound energy. It can be used for distance measurement, speed measurement, cleaning, welding, gravel, sterilization, etc. There are many applications in medicine, military, industry and agriculture.

Reversing radar: When reversing, using the ultrasonic principle, the ultrasonic wave is sent by the probe (transducer) installed on the rear bumper. After hitting the obstacle, it is reflected to form an echo. The probe receives the echo and calculates the distance between the vehicle body and the obstacle. actual distance.

Transducer is an important device in sonar (SONAR), which is a device for mutual conversion between acoustic energy, mechanical energy, electrical energy, and magnetic energy. There are two purposes: one is to transmit sound waves underwater, called "transmitting transducer", which is equivalent to a speaker in the air (commonly known as "microphone"); the other is to receive sound waves underwater, called "receiving transducer". ”, which is equivalent to a microphone in the air (commonly known as an “earpiece”). In actual use, the transducer is often used to transmit and receive sound waves at the same time, and the transducer specially used for receiving sound waves is also called "hydrophone".

There are many more applications of ultrasound, far more than the two mentioned in the text. If humans lose ultrasound, the first thing they can think of is to reverse the car and return to the original era of "looking at the rearview mirror". For some drivers, it will be a game. "Nightmare". The sea is mysterious and powerful. Ultrasound helps human beings to explore the ocean. Without it, perhaps human beings will not be able to explore deeper oceans and understand the secrets of the sea!