Floyd Alburn Firestone (Shiloh Shiloh, Richland County, Ohio, OH, 1898–1986) was an acoustical physicist. In 1940 while a professor at the

University of Michigan The University of Michigan (U-M, U of M, or Michigan) is a public university, public research university in Ann Arbor, Michigan, United States. Founded in 1817, it is the oldest institution of higher education in the state. The University of Mi ...

invented the first practical

ultrasonic testing Ultrasonic testing (UT) is a family of non-destructive testing techniques based on the propagation of ultrasonic waves in the object or material tested. In most common UT applications, very short ultrasonic pulse waves with centre frequencie ...

method and apparatus.Beyer, R.T. (1999). ''Sounds of our times: 200 years of acoustics''. New York, New York: Springer-Verlag, pp. 246-247. He was granted for the invention in 1942. Manufactured by

Sperry Corporation Sperry Corporation was a major American equipment and electronics company whose existence spanned more than seven decades of the 20th century. Sperry ceased to exist in 1986 following a prolonged hostile takeover bid engineered by Burroughs ...

, the testing device was known variously as the Firestone-Sperry Reflectoscope, the Sperry Ultrasonic Reflectoscope, the Sperry Reflectoscope and sometimes also just as a Supersonic Reflectoscope, the name Firestone had coined for the instrument. The technology is not just used in quality control in factories to reject defective parts before shipment, but also revolutionized transportation safety. For example, ultrasonic testing is used for safety maintenance inspection of railroad cars, particularly axles and wheels, aircraft, particularly fuselages, and other transportation vessels for material fatigue. Dr. Firestone's ultrasonic pulse echo technique for metal defect testing was also later applied in medical diagnosis, giving birth to the field of

Echocardiography Echocardiography, also known as cardiac ultrasound, is the use of ultrasound to examine the heart. It is a type of medical imaging, using standard ultrasound or Doppler ultrasound. The visual image formed using this technique is called an ec ...

and to the field of

Medical Ultrasonography Medical ultrasound includes Medical diagnosis, diagnostic techniques (mainly medical imaging, imaging) using ultrasound, as well as therapeutic ultrasound, therapeutic applications of ultrasound. In diagnosis, it is used to create an image of ...

, generally. Dr. Firestone was the editor of the Journal of the

Acoustical Society of America The Acoustical Society of America (ASA) is an international scientific society founded in 1929 dedicated to generating, disseminating and promoting the knowledge of acoustics and its practical applications. The Society is primarily a voluntary org ...

from 1939 to 1957. Among Firestone's many other inventions, were in a single year an “automatic device for the minute inspection of flaws”, “a new and useful improvement in hook-up of electrical apparatus”, and “ device for measuring noise”, and, even, later a “musical typewriter”. He earned a B.S. from the Case School of Applied Science in 1921, and his Ph.D. from the University of Michigan in 1931. Floyd A. Firestone in January 1925, demonstrated an electrical apparatus for determining the loudness of noise from bearings or other sources, before to the

Society of Automotive Engineers SAE International is a global professional association and standards organization based in Warrendale, Pennsylvania, United States. Formerly the Society of Automotive Engineers, the organization adopted its current name in 2006 to reflect bot ...

meeting. The instrument was a modified audiometer consisted essentially by means of
Wente microphone
combined with a sensitive electronic circuits and alternating current voltmeter; therefore, this was the first time that a full electronic device was used to measure the noise level regardless the source type. In 1933, Firestone proposed an alternative to the mechanical–electrical analogy of

James Clerk Maxwell James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish physicist and mathematician who was responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism an ...

in which force is made the analogy of voltage (the impedance analogy). Firestone's analogy (later called the

mobility analogy The mobility analogy, also called admittance analogy or Firestone analogy, is a method of representing a mechanical system by an analogous electrical system. The advantage of doing this is that there is a large body of theory and analysis techni ...

) makes force the analog of current. In this work he introduced the concept of "through" and "across" variables and demonstrated that there were analogies for these variables in other energy domains, making it possible to treat a complex system as a unified whole in analysis. Firestone's analogy became popular amongst

mechanical filter A mechanical filter is a signal processing filter usually used in place of an electronic filter at radio frequencies. Its purpose is the same as that of a normal electronic filter: to pass a range of signal frequencies, but to block others. ...

designers because it has the property of preserving network topologies when transforming between the mechanical and electrical domains. He was elected a fellow of the

American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of ...

in January 1936. He was a fellow of the

(ASA) and its president from 1943 to 1945. In 1955 Floyd A. Firestone got the Gold Medal Award of the ASA.1955 Gold Medal Award to Dr. Floyd A. Firestone. Acoustical Society News.J. Acoust. Soc. Am. 27, 975–976 (1955) https://doi.org/10.1121/1.1908102

Papers

* * Firestone, Floyd A. (1946). The Supersonic Reflectoscope, An instrument for inspecting the interior of solid parts by means of sound waves. ''Journal of the Acoustical Society of America'', 17(3), 287–299,

Full Article

References

External links

History of NDT-Instrumentation
{{DEFAULTSORT:Firestone, Floyd 1898 births 1986 deaths 20th-century American physicists Acousticians University of Michigan faculty ASA Gold Medal recipients Fellows of the Acoustical Society of America Fellows of the American Physical Society

Papers

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References

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