Page 611 - Instrumentation Reference Book 3E

References 593

Acoustic camera

-%-
Surface

Figur'e 24.41 Bulk ultrasonicscanning.
and after the actual inspection (Carter and Burch mum structure and design of system interface to
1986). The most common use is to enhance C- produce the best aid to manual operators. The
scans by color coding defect areas. Other data use of speech recognition as a form of remote
processing techniques include SAFT (Software control for operators is being examined with
Aperture Focusing Technique) (Doctor et al. great interest.
1986), TOFD (Time of Flight Diffraction) (Carter
198.1); expert systems (Moran and Bower 1987),
and neural networks (Windsor et al. 1993). 24.8 Certification of personnel
One of the most interesting innovations in this
field is the concept of an integrated NDT work- No overview of non-destructive testing would be
bench (McNab and Dunlop 1993). These work- complete without some reference to the various
benches provide the hardware and software operator-certification schemes currently in use
systems required to design, carry out, and analyze worldwide. The range of products. processes and
an ultrasonic inspection, all operated from a sin- materials to which such methods have been
gle computer. In theory, such a system would applied has placed increasing demands on the
include a CAD package to provide the exact skills and abilities of its practitioners. Quality
geometry of the part under inspection, controllers assurance requires not only the products to have
fitness for purpose but also the relevant personnel.
to move a mechanical probe over the inspection Developments in various countries in operator
area, digital signal processing software to certification for non-destructive testing are given
enhance the incoming data, and an expert system by Drury (1979).
to help assess the results.
The use of mechanical devices to take inspec-
tions is becoming more common (Mudge 1985),
especially in the nuclear and pressure vessel 24.9 References
industries. Due to the inflexibility of these
mechanical systems, however, the majority of BS 3683. Glossary of Ternis used ir7 Xon-destructive
inspections are still performed by a manual Testiiig-Purt 3 Radiological Flaw Detection (1964)
operator. Designers of NDT equipment are now BS 3971, Image Quality Iiidications (1966)
turning their attention to how computer technol- BS 4094, Recoiiiii~mdutioi~ for Datu on Shielding from
Ionising Radiation (1966)
ogy can improve the reliability. For this type of Blitz, J., Ultrusonic Methods and Applications. Butter-
equipment, ease of use is a prime consideration, worths, London (1971)
since the operator must be able to concentrate on Carter, P., "Experience with the time-of-flight diffraction
taking the inspection without the distraction of a technique and accompanying portable and versatile
complicated computer system. Work is under way ultrasonic digital recording system." Brit. J. NDT,
at the University of Paisley to determine the opti- 26. 354 (1984)