National Institute of Standards and Technology The University of Michigan AAE LIBRARY PURCHASED THROUGH T he National Institute of Standards and Technology was established in 1988 by Congress to "assist industry in the development of technology . . . needed to improve product quality, to modernize manufacturing processes, to ensure product reliability... and to facilitate rapid commercialization ...of products based on new scientific discoveries." NIST, originally founded as the National Bureau of Standards in 1901, works to strengthen U.S. industry's competitiveness; advance science and engineering; and improve public health, safety, and the environment. One of the agency's basic functions is to develop, maintain, and retain custody of the national standards of measurement, and provide the means and methods for comparing standards used in science, engineering, manufacturing, commerce, industry, and education with the standards adopted or recognized by the Federal Government. As an agency of the U.S. Commerce Department's Technology Administration, NIST conducts basic and applied research in the physical sciences and engineering, and develops measurement techniques, test methods, standards, and related services. The Institute does generic and precompetitive work on new and advanced technologies. NIST's research facilities are located at Gaithersburg, MD 20899, and at Boulder, CO 80303. Major technical operating units and their principal activities are listed below. For more information contact the Publications and Program Inquiries Desk, 301-975-3058. Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the entities, materials, or equipment are necessarily the best available for the purpose. National Institute of Standards and Technology Special Publication 973 U.S. GOVERNMENT PRINTING OFFICE WASHINGTON: 2002 For sale by the Superintendent of Documents, U.S. Government Printing Office итти 81402 CONTENTS Dr. B. Zheng, EWI, Columbus, Ohio.......... Optimization of PGMAW Using Online Observation and Statistical Data S. Nordbruch, University of Bremen, Germany Through the Arc Tracking of 5G Narrow Gap Pipe Welds T. S. Rajagopalan, CRC-Evans Automatic Welding, Houston, Texas Development of Rotating GMA Welding System and its Application to A System for Real-Time Control of Gas Metal Arc Weld Profile Dr. D. M. Barborak, WeldWare Inc., Columbus, Ohio............ Dr. M. J. M. Hermans, Delft University of Technology, The Netherlands Real-Time Molten Pool Area Extraction for Control of Gas Tungsten |