Improved signal processing broadens ultrasonics use in solids level measurement
Level measurement using ultrasonics -- the use of sound traveling through air -- is no longer limited to liquid applications or ideal environmental conditions. Improvements in ultrasonic signal processing, including transducer design, microprocessor control, digital filtering, and echo extraction algorithms, allow you to accurately and reliably measure solids levels under various conditions. This article briefly discusses how ultrasonic level measurement works and then describes the recent improvements in signal processing techniques.
Using ultrasonics to measure the distance between two objects isn't a new technology. Common use has included measuring the levels of liquids or slurries, highly reflective and large solids [such as aggregates], materials at short distances [less than 30 feet], and materials in inactive processes [where there's no motion or dust and the material's angle of repose is moderate]. What's new are improvements in ultrasonic signal processing that allow you to measure the levels of small and fine solids [such as carbon black and fly ash], materials at long distances [more than 200 feet], and materials in active processes [where there's motion, other conditions can vary, and the material's angle of repose is steep].