THICKNESS MEASUREMENT OF NON-METALLIC MATERIALS PROGRESS REPORT NO. 4

Document Type: 
Collection: 
Document Number (FOIA) /ESDN (CREST): 
CIA-RDP78-03172A000300050046-5
Release Decision: 
RIPPUB
Original Classification: 
C
Document Page Count: 
5
Document Creation Date: 
December 22, 2016
Document Release Date: 
April 10, 2012
Sequence Number: 
46
Case Number: 
Publication Date: 
May 13, 1957
Content Type: 
REPORT
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PDF icon CIA-RDP78-03172A000300050046-5.pdf153.25 KB
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Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03172A000300050046-5 Project No. A-100 THICKNESS MEASUREMENT OF NON-METALLIC MATERIALS Progress Report No. 4 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03172A000300050046-5 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03172A000300050046-5 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03172A000300050046-5 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03172A000300050046-5 Project No. A-100 THICKNESS MEASUREMENT OF NON-METALLIC MATERIALS Progress Report No. 4 Copy No. May 13, 1957 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03172A000300050046-5 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03172A000300050046-5 THICKNESS MEASUREMENT OF NON-METALLIC MATERIALS L. INTRODUCTION This is a report of the work done on Project No. A- 100 during the period of April I to April 30., 1957. The purpose of this project is the development of an ultrasonic method for measuring thick- ness in non-metallic materials. The material which has been the chief concern to date is concrete, and the method most considered has been the echo method, although a small amount of time during the last month has been used to investigate the possibility of using the barium titanate discs recently obtained as transducers in a resonance type thickness measurement. U. PRESENT WORK Whatever method it used, it is important to have a transducer which, in its mounting, is highly damped. This will allow the production of short bursts of ultrasound for the echo technique or, alternately, will insure the absence of a spurious reading in the resonance method. Much of the time spent during the last month has been given to the investigation of methods for obtaining this damping. Some of the more promising seem to involve the use of a second ceramic transducer, similar to the actual transmitter, which is placed on top of the transmitter, the boundary between the two transducers being a common electrical contact. In one experiment the top transducer bad its two faces shorted or connected through a resistance while the bottom transducer was pulsed. In another experiment the top and bottom faces of the transducer "sandwich" were connected together to ground while the common faces received the pulse from the generator. The best results were obtained when the polarities Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03172A000300050046-5 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03172A000300050046-5 .2. of the two transducers in the sandwich were opposite in direction. The reason for this result is not obvious since, inasmuch as the fields on the two transducers are also opposite in direction, the transducers should oscillate in phase with each other. M. FUTURE WORK Is. This last effect will be investigated during the next month as a part of a continued investigation of damping. A new supplier of barium titanate ceramics has been contacted and has promised to send several samples for our investigation*,, IV. NOTEBOOKS The work reported here is beg recorded in Notebook No. C-6629. V. CONTRIBUTING PERSONNEL The project is under the supervision of The work on the transducers is being done by Respectfully submitted, and 0 7 MR 25X1 25X1 25X1 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03172A000300050046-5