Marcello Pirani
Encyclopedia
Marcello Stefano Pirani was a German
physicist
known for his invention of the Pirani vacuum gauge, a vacuum gauge based on the principle of heat loss measurement. Throughout his career, he worked on advancing lighting technology and pioneered work on the physics of gas discharge.
.
From 1899, Marcello Pirani studied mathematics
and physics
at the University of Berlin. In 1903, he was granted a PhD
for his measurements of the dielectric
constant of solids in the group of Emil Warburg
. He then moved to the Technical University of Aachen
as an assistant at the Physikalischen Institut of this University.
In 1904, he joins the light bulb factory (Glühlampenwerk) of Siemens & Halske
AG in Berlin where he remained for the next fifteen years. At the age of 25, in 1905, he was promoted head of the development lab of the light bulb factory.
In 1906, he made his most important invention with the development of a new type of vacuum gauge that today bears his name, the Pirani vacuum gauge. It is based on measuring the pressure dependence of heat loss from a hot wire by heat transfer to the surrounding gas and walls. In particular, it employs the change in resistivity of the heated wire (in Pirani’s original work consisting of Tantalum and Platinum, today, Tungsten, Platinum or Nickel is commonly used) with temperature to determine the heat loss. Its useful measurement range lies within 10−4mbar up to 1000mbar.
Four years later, he finished his habilitation on optical measurements of high temperatures and studies on the relationship between temperature and emissivity of hot solids and becomes private docent at the Technical University Berlin-Charlottenburg. During the first world war, he enlisted in the army to deal with scientific-technical problems such as wireless telegraphy
.
In 1918, Pirani was promoted Titular-Professor at the TU Berlin-Charlottenburg. One year later, he co-founded the Deutsche Gesellschaft für Metallkunde (German society for metal science) in Berlin.
From 1919 to 1936, he worked for the newly-formed Osram
company. As head of the scientific-technical bureau, he was in charge of coordinating and pushing scientific work in the field of light bulbs of the three founding companies Siemens & Halske
, AEG
and the Auergesellschaft
. In this time fall his pioneering contributions to the advancement of lighting technology, in particular in the field of gas-discharge lamp
s: In 1922, he was named außerordentlicher Professor at the TU Berlin. In 1928, he became head of the Studiengesellschaft fpr electrical lighting of the Osram GmbH. He authors a textbook on heat generation from electrical sources in 1930.
As a professing Quaker, he left the national socialist Germany in 1936 for England
and joined the research lab of General Electric
Co. Ltd. in Wembley
. There his work focused on gas discharge lamps and high temperature resistant materials. From 1941 to 1947, he serveed as scientific consultant for the British Coal Utilization Research Association in London
, working on new high temperature resistant materials involving carbon
. Between 1947 and 1952, he was scientific consultant for the British-American Research Ltd., also in London.
In 1953, he returned to Germany
as one of the few second world war repatriates with scientific background and moved first to Munich
and from 1955 to his hometown Berlin. In 1954, he took up a consultant position with Osram working on problems in gas discharge, glass and ceramics up to an old age.
On January 11, 1968, Marcello Pirani died in Berlin.
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
known for his invention of the Pirani vacuum gauge, a vacuum gauge based on the principle of heat loss measurement. Throughout his career, he worked on advancing lighting technology and pioneered work on the physics of gas discharge.
Biography
Born July 1, 1880 in BerlinBerlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...
.
From 1899, Marcello Pirani studied mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
and physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
at the University of Berlin. In 1903, he was granted a PhD
PHD
PHD may refer to:*Ph.D., a doctorate of philosophy*Ph.D. , a 1980s British group*PHD finger, a protein sequence*PHD Mountain Software, an outdoor clothing and equipment company*PhD Docbook renderer, an XML renderer...
for his measurements of the dielectric
Dielectric
A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...
constant of solids in the group of Emil Warburg
Emil Warburg
Emil Gabriel Warburg was a German Jewish physicist who during his career was professor of physics at the Universities of Strassburg, Freiburg and Berlin. He was president of the Deutsche Physikalische Gesellschaft 1899-1905. He was a friend of Albert EinsteinHe was a member of the Warburg family...
. He then moved to the Technical University of Aachen
RWTH Aachen
RWTH Aachen University is a research university located in Aachen, North Rhine-Westphalia, Germany with roughly 33,000 students enrolled in 101 study programs....
as an assistant at the Physikalischen Institut of this University.
In 1904, he joins the light bulb factory (Glühlampenwerk) of Siemens & Halske
Siemens & Halske
Siemens & Halske AG was a German electrical engineering company that later became part of Siemens AG.It was founded on 12 October 1847 as Telegraphen-Bauanstalt von Siemens & Halske by Ernst Werner von Siemens and Johann Georg Halske...
AG in Berlin where he remained for the next fifteen years. At the age of 25, in 1905, he was promoted head of the development lab of the light bulb factory.
In 1906, he made his most important invention with the development of a new type of vacuum gauge that today bears his name, the Pirani vacuum gauge. It is based on measuring the pressure dependence of heat loss from a hot wire by heat transfer to the surrounding gas and walls. In particular, it employs the change in resistivity of the heated wire (in Pirani’s original work consisting of Tantalum and Platinum, today, Tungsten, Platinum or Nickel is commonly used) with temperature to determine the heat loss. Its useful measurement range lies within 10−4mbar up to 1000mbar.
Four years later, he finished his habilitation on optical measurements of high temperatures and studies on the relationship between temperature and emissivity of hot solids and becomes private docent at the Technical University Berlin-Charlottenburg. During the first world war, he enlisted in the army to deal with scientific-technical problems such as wireless telegraphy
Wireless telegraphy
Wireless telegraphy is a historical term used today to apply to early radio telegraph communications techniques and practices, particularly those used during the first three decades of radio before the term radio came into use....
.
In 1918, Pirani was promoted Titular-Professor at the TU Berlin-Charlottenburg. One year later, he co-founded the Deutsche Gesellschaft für Metallkunde (German society for metal science) in Berlin.
From 1919 to 1936, he worked for the newly-formed Osram
Osram
Osram, founded 1919, is part of the industry sector of Siemens AG and one of the two leading lighting manufacturers in the world. The name is derived from osmium and Wolfram , as both these elements were commonly used for lighting filaments at the time the company was founded...
company. As head of the scientific-technical bureau, he was in charge of coordinating and pushing scientific work in the field of light bulbs of the three founding companies Siemens & Halske
Siemens & Halske
Siemens & Halske AG was a German electrical engineering company that later became part of Siemens AG.It was founded on 12 October 1847 as Telegraphen-Bauanstalt von Siemens & Halske by Ernst Werner von Siemens and Johann Georg Halske...
, AEG
AEG
Allgemeine Elektricitäts-Gesellschaft was a German producer of electrical equipment founded in 1883 by Emil Rathenau....
and the Auergesellschaft
Auergesellschaft
The industrial firm Auergesellschaft was founded in 1892 with headquarters in Berlin. Up to the end of World War II, Auergesellschaft had research activities in the areas of gas mantles, luminescence, rare earths, radioactivity, and uranium and thorium compounds. In 1934, the corporation was...
. In this time fall his pioneering contributions to the advancement of lighting technology, in particular in the field of gas-discharge lamp
Gas-discharge lamp
Gas-discharge lamps are a family of artificial light sources that generate light by sending an electrical discharge through an ionized gas, i.e. a plasma. The character of the gas discharge critically depends on the frequency or modulation of the current: see the entry on a frequency classification...
s: In 1922, he was named außerordentlicher Professor at the TU Berlin. In 1928, he became head of the Studiengesellschaft fpr electrical lighting of the Osram GmbH. He authors a textbook on heat generation from electrical sources in 1930.
As a professing Quaker, he left the national socialist Germany in 1936 for England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
and joined the research lab of General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
Co. Ltd. in Wembley
Wembley
Wembley is an area of northwest London, England, and part of the London Borough of Brent. It is home to the famous Wembley Stadium and Wembley Arena...
. There his work focused on gas discharge lamps and high temperature resistant materials. From 1941 to 1947, he serveed as scientific consultant for the British Coal Utilization Research Association in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
, working on new high temperature resistant materials involving carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
. Between 1947 and 1952, he was scientific consultant for the British-American Research Ltd., also in London.
In 1953, he returned to Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
as one of the few second world war repatriates with scientific background and moved first to Munich
Munich
Munich The city's motto is "" . Before 2006, it was "Weltstadt mit Herz" . Its native name, , is derived from the Old High German Munichen, meaning "by the monks' place". The city's name derives from the monks of the Benedictine order who founded the city; hence the monk depicted on the city's coat...
and from 1955 to his hometown Berlin. In 1954, he took up a consultant position with Osram working on problems in gas discharge, glass and ceramics up to an old age.
On January 11, 1968, Marcello Pirani died in Berlin.
Awards
- 1933 Honorary member of the Lichttechnischen Gesellschaft
- 1933 Gauß-Weber-Medal of the University Göttingen
- 1961 Federal Cross of Merit 1. class of the Federal Republic of Germany