statohm
The statohm (symbol: statΩ) is the unit of electrical resistance in the electrostatic system of units which was part of the CGS system of units based upon the centimetre, gram and second.{{citation |title=Planet Earth |author=Cesare Emiliani |publisher=Cambridge University Press |year=1992 |isbn=9780521409490 |pages=11–12}}
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 ≘ c2 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 trillion times larger than the ohm and is the largest unit of resistance ever used in any measurement system.H. Arthur Klein, The Science of Measurement: A Historical Survey, p. 448, Courier Corporation, 1974 {{ISBN|0486258394}}. The statohm as a practical unit is as unusably large as the abohm is unusably small.
{{in5}}1 statΩ ≘ c2 × {{10^|-9}} Ω ≈ {{val|8.987552e11}} Ω{{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}}{{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 }}
The sign ≘ denotes 'correspondence' between quantities. Equality does not apply, since the systems of quantities underlying the two systems of units are mutually incompatible.