DocumentCode :
1247032
Title :
Large-area ultrasonic gap profile measurements using two-dimensional PVDF "blanket array" transducers
Author :
Brown, Lewis F.
Author_Institution :
Dept. of Electr. Eng., South Dakota Univ., Brookings, SD, USA
Volume :
42
Issue :
1
fYear :
1995
Firstpage :
120
Lastpage :
126
Abstract :
A technique is described for utilizing two-dimensional ultrasonic transducer arrays to accurately measure the spacing (i.e., the gap profile) between large-area mating surfaces. The acoustic measurement theory for pulse-echo and pitch-catch gap profile measurements is derived from a generalized KLM model representation of ultrasonic transducers located within the gap between two mating structures. Expressions for the ultrasonically measured gap spacing are derived in terms of the thicknesses and longitudinal acoustic velocities of the constituent layers of the transducer element(s), adhesive layers(s), and gap medium. Extremely thin PVDF two-dimensional arrays were fabricated and adhered to the inside of a precision gap profile device for demonstrating the measurement technique. Two-dimensional gap profile measurements were made to /spl plusmn/0.001" accuracy for a variety of gap profiles in the range of 0-0.200" thickness. Gap profile measurements were made with both liquid and air as the gap medium and the results show potential for measuring otherwise inaccessible gap profiles between structures.<>
Keywords :
acoustic arrays; distance measurement; echo; piezoelectric transducers; ultrasonic measurement; ultrasonic transducer arrays; 0 to 0.200 in; KLM model representation; acoustic measurement theory; large-area mating surfaces; longitudinal acoustic velocities; pitch-catch gap profile; precision gap profile device; pulse-echo gap profile; two-dimensional PVDF blanket array transducers; ultrasonic gap profile measurements; ultrasonic transducer arrays; Acoustic devices; Acoustic measurements; Acoustic pulses; Acoustic transducers; Pulse measurements; Thickness measurement; Ultrasonic transducer arrays; Ultrasonic transducers; Ultrasonic variables measurement; Velocity measurement;
fLanguage :
English
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
Publisher :
ieee
ISSN :
0885-3010
Type :
jour
DOI :
10.1109/58.368305
Filename :
368305
Link To Document :
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