Siemens (unit)

Physical unit
Unit name	Siemens
Unit symbol	${\displaystyle \mathrm {S} }$
Physical quantity (s)	Electrical conductance
Formula symbol	${\displaystyle G}$
dimension	${\displaystyle {\mathsf {M^{-1}\;L^{-2}\;T^{3}\;I^{2}}}}$
system	International system of units
In SI units	${\displaystyle \mathrm {1\,S=1\;{\frac {A^{2}\,s^{3}}{kg\,m^{2}}}=1\;{\frac {A}{V}}} }$
Named after	Werner from Siemens
Derived from	Volts , amps
See also: Ohm

Resistance normal from Werner von Siemens . Double-coiled glass tube, originally filled with mercury . Around 1860.

Siemens is the unit of measurement for electrical conductance in the SI and is named after Werner von Siemens . The conductance 1 S is the reciprocal of the electrical resistance 1  Ω . The ohm is the SI unit of electrical resistance:

${\displaystyle \mathrm {S={\frac {1}{\Omega }}={\frac {A}{V}}} }$

In 1860 Siemens had published the article Proposal for a reproducible resistance measure in Poggendorff's Annalen der Physik und Chemie , for details see under Ohm . At the 14th General Conference on Weights and Measures in 1971, it was decided to introduce the unit of measurement.

Mho

Mho is an outdated name for the Siemens unit , the name goes back to William Thomson . The designation Mho ( ohms read backwards) and the symbol ℧ (an upside-down large omega ) express that it is the reciprocal of the unit ohm. They were used until the 1930s, and informally in the USA in the field of electronics.

Individual evidence

1. ↑ Werner Siemens: Proposal for a reproducible measure of resistance . In: Annals of Physics and Chemistry . tape 186 , no. 5 , 1860, p. 1-20 , doi : 10.1002 / andp.18601860502 .
2. ^ Minutes of the 14th General Conference on Weights and Measures , 1971, p. 78, accessed Nov. 11, 2019
3. ↑ William Maver: American Telegraphy and Encyclopedia of the Telegraph: Systems, Apparatus, operation , 1903rd