ASM INTERNATIONAL ® The Materials Information Company Publication Information and Contributors Nondestructive Evaluation and Quality Control was published in 1989 as Volume 17 of the 9th Edition Metals Handbook. With the second printing (1992), the series title was changed to ASM Handbook. The Volume was prepared under the direction of the ASM Handbook Committee. Authors and Reviewers • LAMET UFRGS • D.A. Aldrich Idaho National Engineering Laboratory EG&G Idaho, Inc. • Craig E. Anderson Nuclear Energy Services • Gerald L. Anderson American Gas and Chemical Company • Glenn Andrews Ultra Image International • Bruce Apgar DuPont NDT Systems • R.A. Armistead Advanced Research and Applications Corporation • Ad Asead University of Michigan at Dearborn • David Atherton Queen's University • Yoseph Bar-Cohen Douglas Aircraft Company McDonnell Douglas Corporation • R.C. Barry Lockheed Missiles & Space Company, Inc. • John Bassart Iowa State University • George Becker DuPont NDT Systems • R.E. Beissner Southwest Research Institute • Alan P. Berens University of Dayton Research Institute • Harold Berger Industrial Quality, Inc. • Henry Bertoni Polytechnic University of New York • R.A. Betz Lockheed Missiles & Space Company, Inc. • Craig C. Biddle United Technologies Research Center • Kelvin Bishop Tennessee Valley Authority • Carl Bixby Zygo Corporation • Dave Blackham Consultant • Gilbert Blake Wiss, Janney, Elstner Associates • James Bolen Northrop Aircraft Division • Jim Borges Intec Corporation • J.S. Borucki Ardox Inc. • Richard Bossi Boeing Aerospace Division The Boeing Company • Byron Brendan Battelle Pacific Northwest Laboratories • G.L. Burkhardt Southwest Research Institute • Paul Burstein Skiametrics, Inc. • Willard L. Castner National Aeronautics and Space Administration Lyndon B. Johnson Space Center • V.S. Cecco Atomic Energy of Canada, Ltd. Chalk River Nuclear Laboratories • Francis Chang General Dynamics Corporation • Tsong-how Chang University of Wisconsin, Milwaukee • F.P. Chiang Laboratory for Experimental Mechanics Research State University of New York at Stony Brook • D.E. Chimenti Wright Research & Development Center Wright-Patterson Air Force Base • P. Cielo National Research Council of Canada Industrial Materials Research Institute • T.N. Claytor Los Alamos National Laboratory • J.M. Coffey CEGB Scientific Services • J.F. Cook Idaho National Engineering Laboratory EG&G Idaho, Inc. • Thomas D. Cooper Wright Research & Development Center Wright-Patterson Air Force Base • William D. Cowie United States Air Force Aeronautical Systems Division • L.D. Cox General Dynamics Corporation • Robert Cribbs Folsom Research Inc. • J.P. Crosson Lucius Pitkin, Inc. • Darrell Cutforth Argonne National Laboratory • William Dance LTV Missiles & Electronics Group • Steven Danyluk University of Illinois • Oliver Darling Spectrum Marketing, Inc. • E.A. Davidson Wright Research & Development Center Wright-Patterson Air Force Base • Vance Deason EG&G Idaho, Inc. • John DeLong Philadelphia Electric Company • Michael J. Dennis NDE Systems & Services General Electric Company • Richard DeVor University of Illinois at Urbana-Champaign • Robert L. Ditz GE Aircraft Engines General Electric Company • Kevin Dooley University of Minnesota • Thomas D. Dudderar AT&T Bell Laboratories • Charles D. Ehrlich National Institute of Standards & Technology • Ralph Ekstrom University of Nebraska Lincoln • Robert Erf United Technologies Research Center • K. Erland United Technologies Corporation Pratt & Whitney Group • J.L. Fisher Southwest Research Institute • Colleen Fitzpatrick Spectron Development Laboratory • William H. Folland United Technologies Corporation Pratt & Whitney Group • Joseph Foster Texas A&M University • Kenneth Fowler Panametrics, Inc. • E.M. Franklin Argonne National Laboratory Argonne West • Larry A. Gaylor Dexter Water Management Systems • David H. Genest Brown & Sharpe Manufacturing Company • Dennis German Ford Motor Company • Ron Gerow Consultant • Scott Giacobbe GPU Nuclear • Robert S. Gilmore General Electric Research and Development Center • J.N. Gray Center for NDE Iowa State University • T.A. Gray Center for NDE Iowa State University • Robert E. Green, Jr. The Johns Hopkins University • Arnold Greene Micro/Radiographs Inc. • Robert Grills Ultra Image International • Donald Hagemaier Douglas Aircraft Company McDonnell Douglas Corporation • John E. Halkias General Dynamics Corporation • Grover L. Hardy Wright Research & Development Center Wright-Patterson Air Force Base • Patrick G. Heasler Battelle Pacific Northwest Laboratories • Charles J. Hellier Hellier Associates, Inc. • Edmond G. Henneke Virginia Polytechnic Institute and State University • B.P. Hildebrand Failure Analysis Associates, Inc. • Howard E. Housermann ZETEC, Inc. • I.C.H. Hughes BCIRA International Centre • Phil Hutton Battelle Pacific Northwest Laboratories • Frank Iddings Southwest Research Institute • Bruce G. Isaacson Bio-Imaging Research, Inc. • W.B. James Hoeganaes Corporation • D.C. Jiles Iowa State University • Turner Johnson Brown & Sharpe Manufacturing Company • John Johnston Krautkramer Branson • William D. Jolly Southwest Research Institute • M.H. Jones Los Alamos National Laboratory • Gail Jordan Howmet Corporation • William T. Kaarlela General Dynamics Corporation • Robert Kalan Naval Air Engineering Center • Paul Kearney Welch Allyn Inc. • William Kennedy Canadian Welding Bureau • Lawrence W. Kessler Sonoscan, Inc. • Thomas G. Kincaid Boston University • Stan Klima NASA Lewis Research Center • Kensi Krzywosz Electric Power Research Institute Nondestructive Evaluation Center • David Kupperman Argonne National Laboratory • H. Kwun Southwest Research Institute • J.W. Lincoln Wright Research & Development Center Wright-Patterson Air Force Base • Art Lindgren Magnaflux Corporation • D. Lineback Measurements Group, Inc. • Charles Little Sandia National Laboratories • William Lord Iowa State University • D.E. Lorenzi Magnaflux Corporation • Charles Loux GE Aircraft Engines General Electric Company • A. Lucero ZETEC, Inc. • Theodore F. Luga Consultant • William McCroskey Innovative Imaging Systems, Inc. • Ralph E. McCullough Texas Instruments, Inc. • William E.J. McKinney DuPont NDT Systems • Brian MacCracken United Technologies Corporation Pratt & Whitney Group • Ajit K. Mal University of California, Los Angeles • A.R. Marder Energy Research Center Lehigh University • Samuel Marinov Western Atlas International, Inc. • George A. Matzkanin Texas Research Institute • John D. Meyer Tech Tran Consultants, Inc. • Morey Melden Spectrum Marketing, Inc. • Merlin Michael Rockwell International • Carol Miller Wright Research & Development Center Wright-Patterson Air Force Base • Ron Miller MQS Inspection, Inc. • Richard H. Moore CMX Systems, Inc. • Thomas J. Moran Consultant • John J. Munro III RTS Technology Inc. • N. Nakagawa Center for NDE Iowa State University • John Neuman Laser Technology, Inc. • H.I. Newton Babcock & Wilcox • G.B. Nightingale General Electric Company • Mehrdad Nikoonahad Bio-Imaging Research, Inc. • R.C. O'Brien Hoeganaes Corporation • Kanji Ono University of California, Los Angeles • Vicki Panhuise Allied-Signal Aerospace Company Garrett Engine Division • James Pellicer Staveley NDT Technologies, Inc. • Robert W. Pepper Textron Specialty Materials • C.C. Perry Consultant • John Petru Kelly Air Force Base • Richard Peugeot Peugeot Technologies, Inc. • William Plumstead Bechtel Corporation • Adrian Pollock Physical Acoustic Corporation • George R. Quinn Hellier Associates, Inc. • Jay Raja Michigan Technological University • Jack D. Reynolds General Dynamics Corporation • William L. Rollwitz Southwest Research Institute • A.D. Romig, Jr. Sandia National Laboratories • Ward D. Rummel Martin Marietta Astronautics Group • Charles L. Salkowski National Aeronautics and Space Administration Lyndon B. Johnson Space Center • Thomas Schmidt Consultant • Gerald Scott Martin Marietta Manned Space Systems • D.H. Shaffer Westinghouse Electric Corporation Research and Development Center • Charles N. Sherlock Chicago Bridge & Iron Company • Thomas A. Siewert National Institute of Standards and Technology • Peter Sigmund Lindhult & Jones, Inc. • Lawrence W. Smiley Reliable Castings Corporation • James J. Snyder Westinghouse Electric Company Oceanic Division • Doug Steele GE Aircraft Engines General Electric Company • John M. St. John Caterpillar, Inc. • Bobby Stone Jr. Kelly Air Force Base • George Surma Sundstrand Aviation Operations • Lyndon J. Swartzendruber National Institute of Standards and Technology • Richard W. Thams X-Ray Industries, Inc. • Graham H. Thomas Sandia National Laboratories • R.B. Thompson Center for NDE Iowa State University • Virginia Torrey Welch Allyn Inc. • James Trolinger Metro Laser • Michael C. Tsao Ultra Image International • Glen Wade University of California, Santa Barbara • James W. Wagner The Johns Hopkins University • Henry J. Weltman General Dynamics Corporation • Samuel Wenk Consultant • Robert D. Whealy Boeing Commercial Airplane Company • David Willis Allison Gas Turbine Division General Motors Corporation • Charles R. Wojciechowski NDE Systems and Services General Electric Company • J.M. Wolla U.S. Naval Research Laboratory • John D. Wood Lehigh University • Nello Zuech Vision Systems International Foreword Volume 17 of Metals Handbook is a testament to the growing importance and increased sophistication of methods used to nondestructively test and analyze engineered products and assemblies. For only through a thorough understanding of modern techniques for nondestructive evaluation and statistical analysis can product reliability and quality control be achieved and maintained. As with its 8th Edition predecessor, the aim of this Volume is to provide detailed technical information that will enable readers to select, use, and interpret nondestructive methods. Coverage, however, has been significantly expanded to encompass advances in established techniques as well as introduce the most recent developments in computed tomography, digital image enhancement, acoustic microscopy, and electromagnetic techniques used for stress analysis. In addition, material on quantitative analysis and statistical methods for design and quality control (subjects covered only briefly in the 8th Edition) has been substantially enlarged to reflect the increasing utility of these disciplines. Publication of Volume 17 also represents a significant milestone in the history of ASM International. This Volume completes the 9th Edition of Metals Handbook, the largest single source of information on the technology of metals that has ever been compiled. The magnitude, respect, and success of this unprecedented reference set calls for a special tribute to its many supporters. Over the past 13 years, the ASM Handbook Committee has been tireless in its efforts, ASM members have been unflagging in their support, and the editorial staff devoted and resourceful. Their efforts, combined with the considerable knowledge and technical expertise of literally thousands of authors, contributors, and reviewers, have resulted in reference books which are comprehensive in coverage and which set the highest standards for quality. To all these men and women, we extend our most sincere appreciation and gratitude. Richard K. Pitler President, ASM International Edward L. Langer Managing Director, ASM International Preface The subject of nondestructive examination and analysis of materials and manufactured parts and assemblies is not new to Metals Handbook. In 1976, Volume 11 of the 8th Edition Nondestructive Inspection and Quality Control provided what was at that time one of the most thorough overviews of this technology ever published. Yet in the relatively short time span since then, tremendous advances and improvements have occurred in the field so much so that even the terminology has evolved. For example, in the mid-1970s the examination of an object or material that did not render it unfit for use was termed either nondestructive testing (NDT) or nondestructive inspection (NDI). Both are similar in that they involve looking at (or through) an object to determine either a specific characteristic or whether the object contains discontinuities, or flaws. The refinement of existing methods, the introduction of new methods, and the development of quantitative analysis have led to the emergence of a third term over the past decade, a term representing a more powerful tool. With nondestructive evaluation (NDE), a discontinuity can be classified by its size, shape, type, and location, allowing the investigator to determine whether or not the flaw is acceptable. The title of the present 9th Edition volume was modified to reflect this new technology. Volume 17 is divided into five major sections. The first contains four articles that describe equipment and techniques used for qualitative part inspection. Methods for both defect recognition (visual inspection and machine vision systems) and dimensional measurements (laser inspection and coordinate measuring machines) are described. In the second section, 24 articles describe the principles of a wide variety of nondestructive techniques and their application to quality evaluation of metallic, composite, and electronic components. In addition to detailed coverage of more commonly used methods (such as magnetic particle inspection, radiographic inspection, and ultrasonic inspection), newly developed methods (such as computed tomography, acoustic microscopy, and speckle metrology) are introduced. The latest developments in digital image enhancement are also reviewed. Finally, a special six-page color section illustrates the utility of color-enhanced images. The third section discusses the application of nondestructive methods to specific product types, such as one-piece products (castings, forgings, and powder metallurgy parts) and assemblies that have been welded, soldered, or joined with adhesives. Of particular interest is a series of reference radiographs presented in the article "Weldments, Brazed Assemblies, and Soldered Joints" that show a wide variety of weld discontinuities and how they appear as radiographic images. The reliability of discontinuity detection by nondestructive methods, referred to as quantitative NDE, is the subject of the fourth section. Following an introduction to this rapidly maturing discipline, four articles present specific guidelines to help the investigator determine the critical discontinuity size that will cause failure, how long a structure containing a discontinuity can be operated safely in service, how a structure can be designed to prevent catastrophic failure, and what inspections must be performed in order to prevent failure. The final section provides an extensive review of the statistical methods being used increasingly for design and quality control of manufactured products. The concepts of statistical process control, control charts, and design of experiments are presented in sufficient detail to enable the reader to appreciate the importance of statistical analysis and to organize and put into operation a system for ensuring that quality objectives are met on a consistent basis. This Volume represents the collective efforts of nearly 200 experts who served as authors, contributors of case histories, or reviewers. To all we extend our heartfelt thanks. We would also like to acknowledge the special efforts of Thomas D. Cooper (Wright Research & Development Center, Wright-Patterson Air Force Base) and Vicki E. Panhuise (Allied- Signal Aerospace Company, Garrett Engine Division). Mr. Cooper, a former Chairman of the ASM Handbook Committee, was instrumental in the decision to significantly expand the material on quantitative analysis. Dr. Panhuise organized the content and recruited all authors for the section "Quantitative Nondestructive Evaluation." Such foresight and commitment from Handbook contributors over the years has helped make the 9th Edition of Metals Handbook all 17 volumes and 15,000 pages the most authoritative reference work on metals ever published. The Editors General Information Officers and Trustees of ASM International Officers • Richard K. Pitler President and Trustee Allegheny Ludlum Corporation (retired) • Klaus M. Zwilsky Vice President and Trustee National Materials Advisory Board National Academy of Sciences • William G. Wood Immediate Past President and Trustee Kolene Corporation • Robert D. Halverstadt Treasurer AIMe Associates Trustees • John V. Andrews Teledyne Allvac • Edward R. Burrell Inco Alloys International, Inc. • Stephen M. Copley University of Southern California • H. Joseph Klein Haynes International, Inc. • Gunvant N. Maniar Carpenter Technology Corporation • Larry A. Morris Falconbridge Limited • William E. Quist Boeing Commercial Airplanes • Charles Yaker Howmet Corporation • Daniel S. Zamborsky Consultant • Edward L. Langer Managing Director ASM International Members of the ASM Handbook Committee (1988-1989) • Dennis D. Huffman (Chairman 1986-; Member 1983-) The Timken Company • Roger J. Austin (1984-) ABARIS • Roy G. Baggerly (1987-) Kenworth Truck Company • Robert J. Barnhurst (1988-) Noranda Research Centre • Peter Beardmore (1986-1989) Ford Motor Company • Hans Borstell (1988-) Grumman Aircraft Systems • Gordon Bourland (1988-) LTV Aerospace and Defense Company • Robert D. Caligiuri (1986-1989) Failure Analysis Associates • Richard S. Cremisio (1986-1989) Rescorp International, Inc. • Gerald P. Fritzke (1988-) Metallurgical Associates • J. Ernesto Indacochea (1987-) University of Illinois at Chicago • John B. Lambert (1988-) Fansteel Inc. • James C. Leslie (1988-) Advanced Composites Products and Technology • Eli Levy (1987-) The De Havilland Aircraft Company of Canada • Arnold R. Marder (1987-) Lehigh University • John E. Masters (1988-) American Cyanamid Company • L.E. Roy Meade (1986-1989) Lockheed-Georgia Company • Merrill L. Minges (1986-1989) Air Force Wright Aeronautical Laboratories • David V. Neff (1986-) Metaullics Systems • Dean E. Orr (1988-) Orr Metallurgical Consulting Service, Inc. • Ned W. Polan (1987-1989) Olin Corporation • Paul E. Rempes (1986-1989) Williams International • E. Scala (1986-1989) Cortland Cable Company, Inc. • David A. Thomas (1986-1989) Lehigh University • Kenneth P. Young (1988-) AMAX Research & Development Previous Chairmen of the ASM Handbook Committee • R.S. Archer (1940-1942) (Member, 1937-1942) • L.B. Case (1931-1933) (Member, 1927-1933) • T.D. Cooper (1984-1986) (Member, 1981-1986) • E.O. Dixon (1952-1954) (Member, 1947-1955) • R.L. Dowdell (1938-1939) (Member, 1935-1939) • J.P. Gill (1937) (Member, 1934-1937) • J.D. Graham (1966-1968) (Member, 1961-1970) • J.F. Harper (1923-1926) (Member, 1923-1926) • C.H. Herty, Jr. (1934-1936) (Member, 1930-1936) • J.B. Johnson (1948-1951) (Member, 1944-1951) • L.J. Korb (1983) (Member, 1978-1983) • R.W.E. Leiter (1962-1963) (Member, 1955-1958, 1960-1964) • G.V. Luerssen (1943-1947) (Member, 1942-1947) • G.N. Maniar (1979-1980) (Member, 1974-1980) • J.L. McCall (1982) (Member, 1977-1982) • W.J. Merten (1927-1930) (Member, 1923-1933) • N.E. Promisel (1955-1961) (Member, 1954-1963) • G.J. Shubat (1973-1975) (Member, 1966-1975) • W.A. Stadtler (1969-1972) (Member, 1962-1972) • R. Ward (1976-1978) (Member, 1972-1978) • M.G.H. Wells (1981) (Member, 1976-1981) • D.J. Wright (1964-1965) (Member, 1959-1967) Staff ASM International staff who contributed to the development of the Volume included Joseph R. Davis, Manager of Handbook Development; Kathleen M. Mills, Manager of Book Production; Steven R. Lampman, Technical Editor; Theodore B. Zorc, Technical Editor; Heather J. Frissell, Editorial Supervisor; George M. Crankovic, Editorial Coordinator; Alice W. Ronke, Assistant Editor; Jeanne Patitsas, Word Processing Specialist; and Karen Lynn O'Keefe, Word Processing Specialist. Editorial assistance was provided by Lois A. Abel, Wendy L. Jackson, Robert T. Kiepura, Penelope Thomas, and Nikki D. Wheaton. The Volume was prepared under the direction of Robert L. Stedfeld, Director of Reference Publications. Conversion to Electronic Files ASM Handbook, Volume 17, Nondestructive Evaluation and Quality Control was converted to electronic files in 1998. The conversion was based on the fifth printing (1997). No substantive changes were made to the content of the Volume, but some minor corrections and clarifications were made as needed. ASM International staff who contributed to the conversion of the Volume included Sally Fahrenholz-Mann, Bonnie Sanders, Marlene Seuffert, Gayle Kalman, Scott Henry, Robert Braddock, Alexandra Hoskins, and Erika Baxter. The electronic version was prepared under the direction of William W. Scott, Jr., Technical Director, and Michael J. DeHaemer, Managing Director. Copyright Information (for Print Volume) Copyright © 1989 ASM International. All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the written permission of the copyright owner. First printing, September 1989 Second printing, May 1992 Third printing, May 1994 Fourth printing, January 1996 Fifth printing, December 1997 ASM Handbook is a collective effort involving thousands of technical specialists. It brings together in one book a wealth of information from world-wide sources to help scientists, engineers, and technicians solve current and long-range problems. Great care is taken in the compilation and production of this Volume, but it should be made clear that no warranties, express or implied, are given in connection with the accuracy or completeness of this publication, and no responsibility can be taken for any claims that may arise. Nothing contained in the ASM Handbook shall be construed as a grant of any right of manufacture, sale, use, or reproduction, in connection with any method, process, apparatus, product, composition, or system, whether or not covered by letters patent, copyright, or trademark, and nothing contained in the ASM Handbook shall be construed as a defense against any alleged infringement of letters patent, copyright, or trademark, or as a defense against any liability for such infringement. Comments, criticisms, and suggestions are invited, and should be forwarded to ASM International. Library of Congress Cataloging-in-Publication Data (for Print Volume) Metals handbook. Includes bibliographies and indexes. Contents: v. 1. Properties and selection v. 2. Properties and selection nonferrous alloysand pure metals [etc.] v. 17. Nondestructiveevaluation and quality control. 1. Metals Handbooks, manuals, etc. I. ASM Handbook Committee. II. ASM International. Handbook Committee. TA459.M43 1978 669 78-14934 ISBN 0-87170-007-7 (v. 1) SAN 204-7586 Visual Inspection Introduction VISUAL INSPECTION is a nondestructive testing technique that provides a means of detecting and examining a variety of surface flaws, such as corrosion, contamination, surface finish, and surface discontinuities on joints (for example, welds, seals, solder connections, and adhesive bonds). Visual inspection is also the most widely used method for detecting and examining surface cracks, which are particularly important because of their relationship to structural failure mechanisms. Even when other nondestructive techniques are used to detect surface cracks, visual inspection often provides a useful supplement. For example, when the eddy current examination of process tubing is performed, visual inspection is often performed to verify and more closely examine the surface disturbance. Given the wide variety of surface flaws that may be detectable by visual examination, the use of visual inspection may encompass different techniques, depending on the product and the type of surface flaw being monitored. This article focuses on some equipment used to aid the process of visual inspection. The techniques and applicability of visual inspection for some products are considered in the Selected References in this article and in the Section "Nondestructive Inspection of Specific Products" in this Volume. The methods of visual inspection involve a wide variety of equipment, ranging from examination with the naked eye to the use of interference microscopes for measuring the depth of scratches in the finish of finely polished or lapped surfaces. Some of the equipment used to aid visual inspection includes: • Flexible or rigid borescopes for illuminating and observing internal, closed or otherwise inacc essible areas • Image sensors for remote sensing or for the development of permanent visual records in the form of photographs, videotapes, or computer-enhanced images • Magnifying systems for evaluating surface finish, surface shapes (profile and contour ga ging), and surface microstructures • Dye and fluorescent penetrants and magnetic particles for enhancing the observation of surface cracks (and sometimes near-surface conditions in the case of magnetic particle inspection) This article will review the use of the equipment listed above in visual inspection, except for dye penetrants and magnetic particles, which are discussed in the articles "Liquid Penetrant Inspection" and "Magnetic Particle Inspection," respectively, in this Volume. Acknowledgements ASM International would like to thank Oliver Darling and Morley Melden of Spectrum Marketing, Inc., for their assistance in preparing the section on borescopes. They provided a draft of a textbook being developed for Olympus Corporation. Thanks are also extended to Virginia Torrey of Welch Allyn, Inc., for the information on videoscopes and to Peter Sigmund of Lindhult and Jones, Inc., for the information on instruments from Lenox, Inc. Visual Inspection Borescopes A borescope (Fig. 1) is a long, tubular optical device that illuminates and allows the inspection of surfaces inside narrow tubes or difficult-to-reach chambers. The tube, which can be rigid or flexible with a wide variety of lengths and diameters, provides the necessary optical connection between the viewing end and an objective lens at the distant, or distal, tip of the borescope. This optical connection can be achieved in one of three different ways: [...]... lengths, and total length The instrument consists of a sensor, the controller, and a computer The sensor emits two laser beams that converge on the surface of the product being measured The light reflected from the product surface exhibits Doppler shifts because of the movement The frequency of the beam pointing toward the source of the product is shifted up, and the beam pointing toward the destination... shown in Fig 4, the location of the image spot is directly related to the standoff distance form the sensor to the object surface; a change in the standoff distance results in a lateral shift of the spot along the sensor array The standoff distance is calculated by the sensor processor Fig 4 Schematic of laser triangulation method of measurement As light strikes the surface, a lens images the point of... precise mathematical relationship to the wire diameter, the wavelength of the laser beam, and the focal length of the lens Because the laser beam wavelength and the lens focal length are known constants of the system, the diameter can be calculated directly from the diffraction pattern measurement Laser triangulation sensors determine the standoff distance between a surface and a microprocessor-based sensor... photodiode array, and signal-processing electronics (Fig 3) The object casts a shadow, or profile image, of the part on the photodiode array A scan of the array determines the edge image location and then the location of the part edges from which the dimension of the part can be determined Fig 2 Self-contained laser bench micrometer Fig 3 Schematic of profile imaging The laser beam passing the edge of a... probe to the datum (Fig 8) Based on user-entered information, the system can automatically compensate for room temperature, humidity, atmospheric pressure, the temperature of the part, and the thermal expansion of the probe The instrument performs gage comparison, maximum and minimum surface deviation, and total indicator reading measurements Simple statistical functions include mean and one standard... wiring that carries the image signal from a charge-coupled device (CCD) imaging sensor at the distal tip These three basic tube designs can have either fixed or adjustable focusing of the objective lens at the distal tip The distal tip also has prisms and mirrors that define the direction and field of view (see Fig 2) These views vary according to the type and application of borescope The design of illumination... alignment, the observer will see the intensity of the recombined beams increasing and decreasing as the light waves from the two paths undergo constructive and destructive interference The cycle of intensity change from one dark fringe to another represents a half wavelength displacement of movable mirror travel, because the path of light corresponds to two times the displacement of the movable mirror If the. .. produces one frequency with a P polarization and another frequency with an S polarization The beam is projected from the laser head to a remote interferometer, where the beam is split at the polarizing beam splitter into its two separate frequencies The frequency with the P polarization becomes the measurement beam, and the frequency with the S polarization becomes the reference beam (Fig 7) Fig 7 Schematic... available for the detection of small defects, such as lumps, in moving-part applications The bench gage is compact and can measure a variety of part sizes quickly and easily (Fig 2) As soon as measurements are taken, the digital readout displays the gaged dimension and statistical data It indicates the total number of measurements taken, the standard deviation, and the maximum, minimum, and mean readings... Materials W.R DeVries and D.A Dornfield, Inspection and Quality Control in Manufacturing Systems, American Society of Mechanical Engineers, 1982 C.W Kennedy and D.E Andrews, Inspection and Gaging, Industrial Press, 1977 Standard Practice for Evaluating and Specifying Textures and Discontinuities of Steel Castings by Visual Examination, ASTM Standard A 802, American Society for Testing and Materials Surface . The Materials Information Company Publication Information and Contributors Nondestructive Evaluation and Quality Control was published in 1989 as Volume 17 of the 9th Edition Metals Handbook Handbook. With the second printing (1992), the series title was changed to ASM Handbook. The Volume was prepared under the direction of the ASM Handbook Committee. Authors and Reviewers •. Publication of Volume 17 also represents a significant milestone in the history of ASM International. This Volume completes the 9th Edition of Metals Handbook, the largest single source of information