Floyd Alburn Firestone (1898–1986) was an acoustical physicist, who in 1940 while a professor at the

University of Michigan , mottoeng = "Arts, Knowledge, Truth" , former_names = Catholepistemiad, or University of Michigania (1817–1821) , budget = $10.3 billion (2021) , endowment = $17 billion (2021)As o ...

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 center frequencies ...

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 US Patent 2,280,226 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 Burrough ...

, 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 originally 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 In materials science, fatigue is the initiation and propagation of cracks in a material due to cyclic loading. Once a fatigue crack has initiated, it grows a small amount with each loading cycle, typically producing striations on some parts o ...

. 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 and to the field of

Medical Ultrasonography Medical ultrasound includes diagnostic techniques (mainly imaging techniques) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscle ...

, 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 orga ...

from 1939 to 1957. Among Firestone's many other inventions in his field are 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”. 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 mathematician and scientist responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and light ...

in which force is made the analogy of voltage (the

impedance analogy The impedance 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 techniques concerning complex electrical systems, especially ...

). Firestone's analogy (now 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 techniq ...

) makes force the analogy 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. T ...

designers because it has the property of preserving network

topologies In mathematics, topology (from the Greek words , and ) is concerned with the properties of a geometric object that are preserved under continuous deformations, such as stretching, twisting, crumpling, and bending; that is, without closing ho ...

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 k ...

in January 1936. He was a fellow of the Acoustical Society of America and its president from 1943 to 1945.

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

See also

References

External links