In fluctuating airflow, continuous air velocity recording is the most reliable method of air velocity measurement. It allows for fast recognition of changes and the calculation of long-term averages. Also, it enables the mine operator to identify when the airflow has decreased to a point requiring action. Using ultrasonic anemometers provides an accurate option for continuous air velocity monit...

* Project supported by the National Science Foundation of China(Grant No. 10972123) Corresponding author: DU Guang-sheng ABSTRACT : The ultrasonic flowmeter has been widely used in the industrial flow measurement. The flow measurement accuracy depends on the relationship of the profile-linear average velocity. But this relationship of the transition zone is not available at present. In this pap...

As a new nondestructive testing method, the accurate measurement of laser ultrasonic velocity is great significance for judging internal crack defects composites, calculating elastic modulus, residual stress and grain size. Based on finite element analysis thermoelastic effect induced vibration, time-of-flight method grating measuring are studied in this paper. Firstly, waveforms point source, ...

%e have measured the surface-acoustic-wave velocities in Ni/V superlattices using both Brillouin scattering and surface-acoustic-wave techniques; the results are in good quantitative agreement. These results confirm earlier reports of phonon-velocity softening in bcc/fcc superlattices and prove that this is a general phenomenon, not a consequence of the measurement method. In addition, we descr...

In this article, experimentally determined values of sound velocity in LPG in a temperature range (–23...+55) °C are presented. The measurements were taken using two industrial LPG samples in a standard five liter pressurized gas tank. The propagation time of a ultrasonic signal with the frequency of 0.7 MHz was measured. To increase the accuracy of measurement, a pulse-phase method was applied...

The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulu...

Ultrasonic flow meters are gaining wide usage in commercial, industrial and medical applications. Major benefits of utilizing this type of flowmeter are higher accuracy, low maintenance (no moving parts), noninvasive flow measurement, and the ability to regularly diagnose health of the meter. This application note is intended as an introduction to ultrasonic time-of-flight (TOF) flow sensing us...

This paper describes the use of air-coupled ultrasonic tomography for the simultaneous measurement of flow and temperature variations in gases. Air-coupled ultrasonic transducers were used to collect through-transmission data from a heated gas jet. A transducer pair was scanned in two-dimensional sections at an angle to the jet, and travel time and amplitude data recorded along various paths in...