An ultrasonic sound pulse is emitted up to 3 times per second from the base of the transducer. The pulse travels through air, reflects against the process medium below and returns to the transducer. The sensor measures the pulse time of flight between sound generation and receipt, and translated this into distance or liquid level height within the vessel.
Application media often has challenging characteristics that can negatively impact level sensor performance and/or installed life. Factors include corrosive, ultrapure, coating, scaling, dirty, ы╙ density, dielectric or conductivity that are poorly suited for contact measurement. Ultrasonic technology is inherently non-contact, and therefore impervious to the above application factors.
The factors to avoid with ultrasonic are extreme foam, vapor, turbulence and installations in flange fittings with tall risers. Foam, vapor and turbulence can absorb and/or deflect away a substantial portion of the return signal. Tall installation fittings can disrupt the acoustic signal path. Appropriate product selection and installation may be critical to overcoming such factors.