| 摘要 |
<p>According to the present invention there is provided a system to perform measurements on liquids, meat, viscous sugar or starch-based materials, and other foodstuffs using air-coupled ultrasound. The technique uses ultrasonic transducers (advantageously capacitive transducers with polymer membranes), to generate ultrasonic signals in air, and to receive these signals after they have passed through the material under test. An ultrasonic pulse-compression process is then applied to increase the sensitivity of signals transmitted through the materials.</p> |
