Results 251 to 260 of about 4,479,393 (285)

Temperature and humidity characterization of air-coupled piezocomposite transducers

2012 IEEE International Ultrasonics Symposium, 2012
Temperature and humidity are present in almost all environmental conditions and they exert influences in the transducer performance. This study emphasizes the influences of temperature and humidity in two types of air-coupled piezocomposite. It presents the reliability and bandwidth stability of the transducer under temperature and humidity variations.
D.J. Costa, V. Tayra, L. E. Segura, F. M. E. Freijo, F. Buiochi   +4 more
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Advances in wide bandwidth air-coupled capacitance transducers

1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium, 2002
Investigations into the field characteristics of an air-coupled ultrasonic capacitance transducer have been performed for a range of transducer configurations. The pressure field of a wide bandwidth silicon backplate capacitance transducer has been scanned in air, and compared to theory based on a plane piston approach. New devices have been fabricated,
D.A. Hutchins, A.G. Bashford, W.M.D. Wright, D.W. Schindel   +3 more
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Study on the high power air-coupled ultrasonic compound transducer

Ultrasonics, 2006
The high power air-coupled compound ultrasonic transducer in flexural vibration is studied. The transducer consists of a sandwich longitudinal piezoelectric transducer and a circular thin plate in flexural vibration. The resonance frequency equation and the equivalent circuit of a circular radiator with clamped boundary condition are derived.
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Air Coupled Ultrasonic Transducers for Industrial Applications

2019
Luftgekoppelte Ultraschallwandler werden in vielen industriellen, medizinischen oder privat-häuslichen Anwendungen benutzt, wie zum Beispiel Entfernungsmessung, Gestenerkennung oder Gas Durch- flussmessung um hier nur einige zu Nennen. Die Kenntnis über das Verhalten und die Eigenschaften von Ultraschallwandlern ist dabei wesentlich für die Entwicklung ...
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Equivalent circuits and directivity patterns of air-coupled ultrasonic transducers

The Journal of the Acoustical Society of America, 2001
Air-coupled transducers for producing ultrasonic radiation in gases are studied. The transducer consists of a circular thin plate in flexural vibration and a sandwich longitudinal electromechanical vibrator that is attached to the center of the plate. The lowest-order axially symmetric flexural vibrational mode of a circular thin plate is analyzed. The
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Air-coupled Transducers for Quality Control in the Food Industry

2019 IEEE International Ultrasonics Symposium (IUS), 2019
Food industry is continuously innovating its capability of analysis by incorporating new technologies aimed to meet increasing quality and safety requirements, concurrence and consumers demands. In this context, non-destructive and non-invasive techniques are demanded in different stages of the production chain for quality control and verification. Air-
Alba Martin Ginel, Tomas Gomez Alvarez-Arenas   +1 more
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Radiated fields of rectangular air-coupled micromachined transducers

2001 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.01CH37263), 2002
The radiated fields of surface micromachined capacitive transducers, with single element sizes in the 2-5 mm range, have been measured experimentally. The transducers have been fabricated using a low temperature CMOS compatible process, and consist of a single metallised PECVD silicon nitride membrane (of typically 1 /spl mu/m thickness), separated by ...
T.J. Robertson, A. Neild, D.A. Hutchins, J.S. McIntosh, D.R. Billson, R.A. Noble, R.R. Davies, L. Koker   +7 more
openaire   +1 more source

The design and characterization of micromachined air-coupled capacitance transducers

IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 1995
Air-coupled capacitance transducers have been manufactured using anisotropically etched silicon backplates and commercially available dielectric films (Kapton and Mylar). The small backplate pits which result from etching, provide well ordered and highly uniform air layers between the backplate surface and thin dielectric film.
D.W. Schindel, D.A. Hutchins, null Lichun Zou, M. Sayer   +3 more
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An air-coupled line-focused capacitive ultrasonic transducer

2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121), 2002
A new type of air-coupled, line-focusing transducer is described. This capacitive broadband device, with an active area measuring 19.5 mm/spl times/45 mm, consists of a metallised 3.5 mm thick polymer film mounted over a brass backplate cylindrically concave along its length, with a radius of 28 mm.
T.J. Robertson, D.A. Hutchins, D.R. Billson   +2 more
openaire   +1 more source

Performance of Spherically Focused Air-Coupled Ultrasonic Transducers

AIP Conference Proceedings, 2007
This paper reports the development, testing, and performance evaluation of spherically focused capacitive air‐coupled ultrasonic transducers 1 and 5 cm in diameter. A flexible micro‐machined copper/polyimide backplate permits a conformal fit to a spherically shaped fixture, forming the rear capacitor plate.
D. E. Chimenti, Junho Song
openaire   +1 more source