A Novel Real-Time Acetic Acid Concentration Detection System Based on Capacitive Micromachined Ultrasonic Transducers

This paper presents a novel ultrasonic acetic acid concentration detection system based on capacitive micromachined ultrasonic transducers (CMUTs). The system utilizes CMUTs as the core sensing components to perform both signal transmission and reception. A temperature sensor is integrated to continuously monitor temperature variations in the test liquid, thereby ensuring measurement accuracy. Under the temperature compensation mechanism, the system continuously analyzes the acquired signals to accurately determine the ultrasonic time-of-flight and propagation velocity in the liquid. A quantitative model correlating sound velocity with temperature and acetic acid concentration was established and experimentally validated, demonstrating excellent stability and high sensitivity. The system achieves a measurement accuracy of 0.35% and a resolution of 0.1%. Benefiting from the miniaturized design of CMUTs, the system can be developed into a compact probe, offering an efficient and convenient solution for real-time acetic acid concentration monitoring during vinegar production and distribution.