Clamp-on ultrasonic transit time difference flow meters provide opportunities for metering where it is impractical or undesirable to cut into an existing pipeline to install an alternative flow meter. Up until now, it has been difficult to perform this type of measurement on thin-walled metal pipes, due to the difficulty of interpreting the guided wave modes in the combined pipe wall and internal fluid system, but a new method has been reported recently that utilises these guided wave modes for flow measurement.

Most of the existing image fusion models.....

The acoustic observation signal of the Penaeus vannamei was used in the application experiment. The experimental address is located in the Penaeus vannamei breeding base in Fengxian District, Shanghai, China. And the passive acoustic hydrophone model was Brüel&Kjær-8103 with high sensitivity −211dB re 1V/μPa. The key parameters of the application experiment were as follows. The hydrophone was placed at 2m depth underwater, the duration of the observation signal was the 90s, the signal sampling frequency was 48kHz, and the data width was 16bit.

Using acoustic waves to estimate fluid concentration is a promising technology due to its practicality and non-intrusive aspect, especially for medical applications. The existing approaches are exclusively based on the correlation between the reflection coefficient and the concentration. However, these techniques are limited by the high sensitivity of the reflection coefficient to environmental conditions changes, even slight ones. This introduces inaccuracies that cannot be tolerated in medical applications.