Views: 3 Author: Site Editor Publish Time: 2019-03-27 Origin: Site
In the industrial production, various sealed liquids are often used to store high-temperature, toxic, volatile, flammable, explosive, and highly corrosive liquid media. For ultrasonic depth transducer of these containers, non-contact measurement must be used.
Ultrasonic testing is a non-destructive test. It is widely used in the industry for flaw detection and thickness detection of metal components,concrete products and ceramic products. In addition, ultrasonic applications are becoming more and more widely used in many fields such as level, game, flow, flow rate, burglar alarm.
The piezoelectric ultrasonic transducer has the advantages of small angle, small dead zone, accurate measurement, no contact, waterproof, anti-corrosion and low cost. It can be applied to liquid level and level detection to ensure stable output when there is foaming sloshing on the liquid surface and it is difficult to detect echo.
Sound waves
It is a mechanical wave that, due to the mechanical vibration of the sounding body, causes vibration of the particle in the surrounding elastic medium and propagates from near to far.
The frequency of sound waves that can be heard by the human ear is in the range of 20 to 20,000 Hz. Frequency is exceeding 20kz called ultrasonic wave, and frequency is lower than 20Hz called infrasound wave. ultrasonic flowmeter transducer commonly used in testing range from a few kilohertz to tens of megahertz. It is the propagation characteristics of ultrasound
Propagation speed
The propagation speed of ultrasonic waves is proportional to the wavelength and frequency. The sound velocity is U=λf where λ is the wavelength of the ultrasonic wave; f is the frequency of the ultrasonic wave.
Acoustic attenuation
When the same medium is used, the ultrasonic wave attenuates as the medium absorbs energy as the propagation speed increases.The degree of absorption of the medium is related to the density and frequency of the medium. Due to the small density of the gas, the ultrasonic wave decays rapidly in the gas, and the attenuation is fast when the frequency is high. Therefore, ultrasonic instruments are mainly used in gases and liquids.
