The theory and design of microwave generators horns

This preview shows page 14 - 16 out of 17 pages.

The theory and design of microwave generators, horns, antennas, detectors and display systems had been developed for long distance ranging in radar. Many textbooks presented the electromagnetic theory of microwaves in terms readily used by electrical engineers. Microwave system components and electron tubes were commercially available. However, electrical engineers were rarely aware of the needs of nondestructive testing engineers, and nondestructive testing engineers had little familiarity with microwaves. In fact, many nondestructive test personnel were still just beginning to use and understand eddy current testing at the lower frequencies. After several years of diligent development, continued application research and marketing efforts by Richard Hochschild with the assistance of Ronald Botsko, the pioneer organization Microwave Instruments Company was sold and its proprietor moved to the area of medical services. A few other organizations built simple microwave test systems but the development of industrial microwave nondestructive testing languished during the 1970s. Limited research sponsored by government agencies resulted in possibilities for crack detection from a distance. The theory of microwave antennas and of time domain reflectometry of microwaves in tubes, passing along wires and reflecting and refracting in dielectric layers, promises the possibility of valuable nondestructive testing applications. Because microwaves can be focused, microwave systems could be designed to operate in a manner analogous to optical instruments and ultrasonic systems. A large scale example of microwave exploration of test objects at great distances is occurring in radio astronomy laboratories throughout the world. Many radio signals from objects billions of kilometers away have been confirmed by films from optical telescopes and the locations of others have been predicted. Emissions are detected from galaxies, black holes and other astronomical features. J.D. Kraus has recognized this as a form of nondestructive testing of outer space and has written a biographical book called The Big Ear, 17 which clearly and simply summarizes a lifetime of study and applications of Maxwell’s theory of electromagnetic fields. 40 Electromagnetic Testing
Image of page 14

Subscribe to view the full document.

1. McMaster, R.C. “The Origins of Electromagnetic Testing.” Materials Evaluation. Vol. 43, No. 8. Columbus, OH: American Society for Nondestructive Testing (July 1986): p 946-956. 2. McMaster, R.C. Section 1, “Introduction to Electromagnetic Testing.” Nondestructive Testing Handbook, second edition: Vol. 4, Electromagnetic Testing. Columbus, OH: American Society for Nondestructive Testing (1986): p 2-12. 3. Millikan, R.A. “Early Views of Electricity.” Electrons (+ and –), Protons, Photons, Neutrons, and Cosmic Rays.
Image of page 15
Image of page 16
  • Fall '19
  • Magnetic Field, James Clerk Maxwell, Nondestructive testing, History of Electromagnetic Testing

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern