Author： Cerniglia Donatella Djordjevic B.
Publisher： Taylor & Francis Ltd
ISSN： 0934-9847
Source： Research in Nondestructive Evaluation, Vol.15, Iss.3, 2004-07, pp. : 111-117
Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.
Abstract
Two non-contact remote ultrasonic detection systems are compared. The first consists of a continuous wave (CW) Nd:YVO4 laser operating at 532 nm used in conjunction with a photo-induced electromotive-force (EMF) sensor. The second system employs an air-coupled capacitance transducer that has a bandwidth from 100 kHz up to 2 MHz. Both systems exhibit higher sensitivity to out-of-plane than in-plane measurements of stress wave signals. Ultrasound generation is carried out by an Nd:YAG pulsed laser at 532 nm in the thermoelastic regime in a 1.6 mm aluminum plate. A0 Lamb mode is generated at frequency-thickness product with strong out-of-plane displacements. Ultrasonic waveforms acquired are reported and the performance advantages of the two remote non-contact detectors are compared with each other. For lower frequency tests (up to 2 MHz), better results have been achieved with the air-coupled transducer that also has superior overall performance and benefits. The tests enabled direct comparison of air-coupled transducer and photo-EMF detector.
Related content
Access to resources
Recommend
By Declercq Nico Teklu A. Breazeale M. A. Hasse Roger Degrieck Joris Leroy Oswald
Research in Nondestructive Evaluation, Vol. 16, Iss. 2, 2005-04 ,pp. :
Influence of transducer-ground coupling on vibration measurements
By Adhikari G. R. Theresraj A. I. Gupta R. N.
Fragblast, Vol. 9, Iss. 2, 2005-06 ,pp. :
The effect of ultrasonic energy on lime slaking
By Potgieter S.S. Strydom C.A. Gheevarhese O.
Minerals Engineering, Vol. 16, Iss. 8, 2003-08 ,pp. :