André Blondel

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André Blondel
Faraday Medal (1937)
Scientific career
FieldsPhysics

André-Eugène Blondel (28 August 1863 – 15 November 1938) was a French engineer and

oscillograph and a system of photometric
units of measurement.

Life

Blondel was born in

School of Mines in Paris.[3]

Very early in his career he suffered immobility due to a paralysis of his legs, which confined him to his room for 27 years, but he never stopped working.[1]

In 1893 André Blondel sought to solve the problem of integral synchronization, using the theory proposed by Cornu. He determined the conditions under which the curve traced by a high-speed recording instrument would follow as closely as possible the actual variations of the physical phenomenon being studied.[2]

This led him to invent the

cathode ray oscilloscope. They paved the way for a greater understanding of the behavior of alternating current.[2]

Blondel built a theory of rectification with asymmetrical electrodes. He demonstrated that there were three kinds of electric arc: the primitive arc of William Duddell, the secondary arc of Valdemar Poulsen, and a succession of oscillatory discharges.[2]

In 1892, he published a study on the coupling of synchronous generators on a large AC electric grid. This analysis had also been done a little earlier by another electrical engineer, Paul Boucherot, using a different approach, and the two authors arrived at similar conclusions.[2]

In 1894 he proposed the lumen and other new measurement units for use in photometry, based on the metre and the Violle candle.[3] He coined the names of the phot and the stilb around 1920.[4]

In 1899, he published Empirical Theory of Synchronous Generators which contained the basic

theory of the two armature reactions (direct and transverse). It was used extensively to explain the properties of salient-pole AC machines.[2]

In 1909, assisted by M. Mähl, he worked on one of the first long distance schemes for the transmission of AC power. The project created a (then) large 300,000 hp

hydroelectric power plant at Genissiat on the Rhône, and transmitted electrical power to Paris more than 350 km away using polyphase AC current at 120 kV.[2]

In 1914 he performed a

series of experiments in order to determine what was the most general law of electromagnetic induction.[5]

He died in Paris on 15 November 1938.

Honours and awards

Blondel was made a member of the

Faraday Medal in 1937. He also received the medal of the Franklin Institute, the Montefiore award and Lord Kelvin award.[3]

In 1942 Parry Moon proposed to rename the unit of luminance apostilb the blondel.[6]

Society

André Blondel was one of the founder members in 1930 of the

Lyons.[7]

See also

Notes

  1. ^ a b See Academie de Poitiers
  2. ^ a b c d e f g See IEEE Industry Applications Magazine May–June 2004
  3. ^ a b c d See Hebrew University of Jerusalem
  4. doi:10.1364/JOSA.32.000348
    . The lumen was proposed by Blondel in 1894 and is now universally accepted. The names, phot and stilb were likewise coined by Blondel (1921) and are in general use on the Continent..
  5. ^ M. André Blondel (1914). "Sur l'énoncé le plus général des lois de l'induction". Comptes rendus hebdomadaires des séances de l'Académie des sciences. 159: 674.
  6. doi:10.1364/JOSA.32.000348
    . The unit is pi times the lumens per square meter per steradian. Such a name is impossibly cumbersome, so a new name is proposed, the blondel, after André Blondel who did pioneer work in photometric nomenclature.
  7. ^ "Bulletin de la Société des Amis d'André-Marie Ampère". Bulletin de la Société des Amis d'André-Marie Ampère (in French). 1. Malkoff (Seine): Société des Amis d'André-Marie Ampère. 1931.

References

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