NAMED UNITS OF MEASUREMENT

• Abbe : Named after Ernst Abbe(1840-1901) who had great contributions in the field of optical instruments. The unit is used to measure Linear Spatial Frequency. Its dimensins are Hz m^-1.
  
• Amagat : Named after E. H. Amagat(1841-1915) who studied gases under high pressures. Amagat volume and Amagat density are used as measures in the study of behaviour of gases under pressure. For both units UNIT PRESSURE is taken as one standard atmosphere pressure. For an ideal gas, the Amagat volume is 22.4 litres. It is the volume occupied by one gram-mole of the gas at unit pressure and 273.15 K.
  
• Ampere : Named after A. M. Ampere(1775-1836) who had major contributions in the field of electricity. It is the unit of electric current.
  
• Angstrom : Named after A. J. Angstrom(1814-1874)who had used 10^-10 m to describe wavelengths. It is a unit of length used generally at atomic levels. It is equal to 10^-10 m.
  
• Balmer : Named after J. J. Balmer(1825-1898) who was a spectroscopist. It is a unit of wave-number and represents the number of waves in one centimeter. It has the dimensions of cm^-1.
  
• Baud : Named after J. M. E. Boudot(1845-1903) who was a French telegraph engineer and had made the first teleprinter. It is a unit of telegraph signalling speed. One baud is equal to one pulse per second.
  
• Becquerel : Named after A. H. Becquerel(1852-1908),a French physicist who discovered radioactivity. It is a unit of radioactivity and 1 becquerel means one nuclear disintegration or nuclear transformation per second.
  
• Clausius : Named after R. J. L. Clausius(1822-1888). It is a unit of entropy.
  
• Coulomb : Named after C. A. Coulomb(1736-1806) who had contributed to the field of electricity as one of the pioneers. It is the unit of electric charge.
  
• Curie : Named after Pierre Curie(1859-1906) who was one of the discoverers of radium. It is a unit of radioactivity.
  
• Darcy : Named after French scientist H. Darcy(1803-1858). He investigated the flow of fluids in porous media. It is the CGS unit of permeability of porous materials.
  
• Einstein : Named after Albert Einstein(1879-1955). Einstein worked in the field of photoelectric effect and gave us the great 'Theory of relativity' for which world better remembers him. It is a unit of photoenergy.
  
• Erlang : Named after the Danish mathematician, A. K. Erlang(1879-1924). It is a telephone traffic unit used to express traffic density.
  
• Farad : Named after Michael Faraday(1791-1867). It is a unit of capacitance.
  
• Fermi : Named after E. Fermi(1901-1954) who built first atomic pile. It is a unit of distance equal to 10^-15 m.
  
• Fresnel : Named after A.J.Fresnel(1788-1827) who was an advocate of wave theory of light. It is a unit of optical frequency (1 fresnel = 10¹² Hz).