View source for Statohm

The '''statohm''' (symbol: statΩ) is the unit of [[electrical resistance]] in the [[electrostatic units|electrostatic system of units]] which was part of the [[Centimetre–gram–second system of units#Derivation of CGS units in electromagnetism|CGS]] system of units based upon the centimetre, gram and second.<ref>{{citation |title=Planet Earth |author=Cesare Emiliani |publisher=Cambridge University Press |year=1992 |isbn=9780521409490 |pages=11–12}}</ref>

The static units in that system are related to the corresponding electromagnetic units by a factor of the [[speed of light]].  Those units are known as absolute units, and so the counterpart of the statohm is the [[abohm]] (abΩ), and their proportions are:

{{in5}}1 statΩ  ≘ ''c''<sup>2</sup> abΩ ≈ {{val|8.987552e20}} abΩ where ''c'' is the speed of light in centimetres per second.

These units are not common now.  The [[SI unit]] of resistance is the [[ohm]] (Ω).  The statohm is nearly a [[Orders of magnitude (numbers)#1012|trillion]] times larger than the ohm and is the largest unit of resistance ever used in any measurement system.<ref>H. Arthur Klein, ''The Science of Measurement: A Historical Survey'', p. 448, Courier Corporation, 1974 {{ISBN|0486258394}}.</ref>  The statohm as a practical unit is as unusably large as the abohm is unusably small.

{{in5}}1 statΩ  ≘ ''c''<sup>2</sup> × {{10^|-9}} Ω ≈ {{val|8.987552e11}} Ω<ref>{{citation |title=Encyclopaedia of Scientific Units, Weights and Measures |last=Cardarelli |first=François |publisher=Springer |year=2003 |isbn=978-1-4471-1122-1 |location=London |page=23}}</ref><ref>{{citation |page=[https://archive.org/details/crchandbookoftab0000unse_y0b1/page/839 839] |title=CRC Handbook of Tables for Applied Engineering Science |author=Ray E. Bolz |publisher=CRC Press |year=1973 |isbn=978-0849302527 |url=https://archive.org/details/crchandbookoftab0000unse_y0b1/page/839 }}</ref>

The sign ≘ denotes 'correspondence' between quantities. Equality does not apply, since the systems of quantities underlying the two systems of units are mutually incompatible.

==References==
{{reflist}}

{{CGS units}}

[[Category:Units of electrical resistance]]
[[Category:Centimetre–gram–second system of units]]