Principles of Ultrasonic Weather Transducer Sensors

Ultrasonic wind transducer is a kind of mechanical oscillation in elastic medium, which has two forms: transverse oscillation (transverse wave) and longitudinal oscillation (longitudinal wave). The application in industry mainly adopts longitudinal oscillation. Ultrasonic waves can propagate in gases, liquids and solids, and their propagation speeds are different. In addition, it also has refraction and reflection phenomena, and attenuation during propagation. Ultrasonic waves propagate in the air, the frequency is low, generally tens of KHZ, while in solids and liquids, the frequency can be higher. The attenuation is faster in the air, while it spreads in liquid and solid, the attenuation is small, and the spread is longer. Utilizing the characteristics of ultrasonic waves, it can be made into various ultrasonic sensors, equipped with different circuits, and made into various ultrasonic measuring instruments and devices, Ultrasonic wind speed sensors are widely used in communication, medical appliances and other aspects.

The main materials of ultrasonic wind sensors are piezoelectric crystal (electrostriction) and nickel-iron-aluminum alloy (magnetostriction). Electrostrictive materials include lead zirconate titanate (PZT) and so on. The ultrasonic sensor composed of piezoelectric crystal is a reversible sensor. It can convert electrical energy into mechanical oscillation to generate ultrasonic waves. At the same time, when it receives ultrasonic waves, it can also be converted into electrical energy, so it can be divided into transmitters or receivers. Some ultrasonic sensors can both send and receive. Only small ultrasonic transducer sensors are introduced here. There is a slight difference between sending and receiving. It is suitable for transmission in the air, and the working frequency is generally 23-25KHZ and 40-45KHZ. This type of sensor is suitable for ranging, remote control, anti-theft and other purposes. There are T/R-40-60, T/R-40-12, etc. (where T means sending, R means receiving, 40 means frequency is 40KHZ, 16 and 12 mean its outer diameter, in millimeters). There is also a sealed ultrasonic sensor (MA40EI type). Its characteristic is that it is waterproof (but can not be put into water),which can be used as a material level and proximity switch, and its performance is better. There are three basic types of ultrasonic applications. The transmissive type is used for remote control, anti-theft alarm, automatic door, proximity switch, etc.; the separated reflective type is used for distance measurement, liquid level or material level; the reflective type is used for material flaw detection, thickness measurement, etc. .