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History of NDT-InstrumentationProf.Dr.-Ing. Volker Deutsch,
I am aware of the fact that such a task can never be completed. Therefore I apologize to all those for excuse who are not mentioned or have quite different memories. In addition I want to point out that I name only those companies which have an considerable export and are not only working in one or few countries.
The first NDT-method coming into industrial application was the X-Ray Technique
Early technical X-ray applications in Germany were realized by Richard Seifert around 1930. He improved medical equipment, cooperated with welding-institutes and built up the small company founded by his father to a world-wide respected name: Richard Seifert Hamburg 13. He got competition by Siemens and C.H.F. Müller, part of the Philips-organisation, who already worked in the medical field. Seifert died in 1969, but his company kept leadership in technical X-ray-application under the direction of his youngest daughter Elisabeth Samusch.
Radiation testing can also be carried out with radioactive isotopes. This was discovered by Mme. Curie. She, born as Maria Sklodowska in Warscaw received the Nobel-prize for physics in 1903 together with her husband Pierre Curie and Henri Becquerel. This was the second award after Röntgen's in 1901. Also radioactive isotopes were initially used for medical applications. In Germany Rudolf Berthold and Otto Vaupel applied them after 1933 to welded joints.
After World War II Arturo Gilardoni in Italy, Drenk and Andreasen in Denmark developed X-ray-equipment, Kurt Sauerwein portable isotope-containers in Germany.
The first European who built a magnetic particle crack detector was an Italian in 1932: Giraudi. His machine was named "Metalloscopio".
In Germany Berthold and Vaupel applied MP-technique to welded constructions. Their equipment was produced by Ernst Heubach. Bruno Suschyzki sold this equipment. He invented swinging field MP-testing.
In Berlin too E.A.W. Müller designed MP-testing machines for Siemens. In Prague the Seifert-representative Karasek began with similar production.
After World War II Wilhelm Tiede, a former Seifert-employee, started his own company in Southern Germany. Through the Seifert-organisation he had connections to Karasek who emigrated to Brazil in 1948 after the communistic revolution in Cechoslovakia. There he continued production of MP-machines.
Starting with dry-powder methods two more companies entered this market in the late Fifties: Karl Deutsch in Germany and CGM (Carlo Gianni Milano) in Italy.
In Sweden Anders Arnelo started similar developments at Svenska Metalverken (SM). He solved the problem to test hot wires and invented the pre-magnetization for ET of ferritic bars.
Other companies followed later: Magnaflux, Hentschel, Law and Zetec in the USA, Rohmann and Prüftechnik Busch & Partner in Germany, Bergstrand in Sweden and Hocking in Britain.
In 1929 the Russian Sokolov proposed to use ultrasound for testing castings. In Berlin Pohlman realized in 1937 an image-cell to indicate the differences of ultrasound-energy similar to a X-ray image-screen.
The detection of laminations in plates and fine non-metallic inclusions in hot-rolled profiles became necessary during World War II. The already existing NDT-methods - X-rays, MP, PT and ET - were unable to solve these problems.
Industrial use of ultrasonic testing started simultaniously in three countries: USA, GB and Germany. The key-persons, Floyd Firestone, Donald O. Sproule and Adolf Trost had no knowledge of each other as they worked strictly in secret. Not even their patent-applications were published. Sproule and Trost used transmission-technique with seperate transmitter- and receiver-probes. Trost invented the so-called "Trost-Tonge". The 2 probes were contacted on opposite sides of a plate, held in same axis by a mechanical device - the tonge - and coupled to both surfaces by continuously flowing water. Sproule placed the 2 probes on the same side of the workpiece. So he invented double-crystal probes. But it has to be mentioned that he used this combination also with variing distance from each other. Firestone was the first to realize the reflection-technique. He modified a radar instrument and developed a transmitter with short pulses and an amplifier with short dead-zone.
Sproule and Firestone found industrial partners for their instruments: Kelvin-Hughes and Sperry Inc.
In Germany 1949 two persons received information about the Firestone-Sperry-Reflectoscope by publications in technical papers: Josef Krautkrämer in Cologne and Karl Deutsch in Wuppertal. Both started developments - without knowledge of each other. Josef Krautkrämer and his brother Herbert were physicists, working in the field of oscilloscopes. They could develop ultrasonic instruments alone. Karl Deutsch, a mechanical engineer needed a partner for the electronics and found him with Hans-Werner Branscheid who had got some technical experience in radar-technique during the war. Within only one year both young and tiny companies could present their UT-flaw-detectors, starting a competition still existing today.
Later on more UT-units came on the international markets: Siemens and Lehfeldt in Germany, Kretztechnik in Austria, Ultrasonique in France and Ultrasonoscope in Britain. They all stopped their production before the 70-ies, Kelvin-Hughes also stopped at the same time, Sperry was later renamed Automation Ind., around 1995.
Krautkrämer became world-wide market-leader in the early 60-ies and has kept this position until today. Besides Karl Deutsch new names came up: Nukem in Germany, Panametrics and Stavely (after Sonic and Harisonic) in USA, Sonatest and Sonomatic in GB, Gilardoni in Italy and Mitsubishi in Japan.
Today more than 50 companies are active in industrial NDT. They are still working under strong competition to the benefit of their customers on their way to improve the quality of industrially produced parts.
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