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The conversion of conductivity (in μS/cm) to the total dissolved solids (in mg/kg) depends on the chemical composition of the sample and can vary between 0.54 and 0.96. Typically, the conversion is done assuming that the solid is sodium chloride; 1 μS/cm is then equivalent to about 0.64 mg of NaCl per kg of water.
The siemens (symbol: S) is the unit of electric conductance, electric susceptance, and electric admittance in the International System of Units (SI). Conductance, susceptance, and admittance are the reciprocals of resistance, reactance, and impedance respectively; hence one siemens is equal to the reciprocal of one ohm (Ω −1) and is also referred to as the mho.
Moreover, similar types of apparatus will have the impedances lying within a narrow numerical range when expressed as a per-unit fraction of the equipment rating, even if the unit size varies widely. Conversion of per-unit quantities to volts, ohms, or amperes requires a knowledge of the base that the per-unit quantities were referenced to.
where is the length of the conductor, measured in metres (m), A is the cross-sectional area of the conductor measured in square metres (m 2), σ is the electrical conductivity measured in siemens per meter (S·m −1), and ρ is the electrical resistivity (also called specific electrical resistance) of the material, measured in ohm-metres (Ω ...
The SI unit of electrical resistivity is the ohm-metre (Ω⋅m). [1] [2] [3] For example, if a 1 m 3 solid cube of material has sheet contacts on two opposite faces, and the resistance between these contacts is 1 Ω, then the resistivity of the material is 1 Ω⋅m.
The term was coined by C.P. Steinmetz in a 1894 paper. [1]In some sources Oliver Heaviside is given credit for coining the term, [2] or with introducing the concept under the name permittance. [3]
If this convention is used, then the values are in the same range as monovalent ions, e.g. 59.5 S cm 2 mol −1 for 1 / 2 Ca 2+ and 80.0 S cm 2 mol −1 for 1 / 2 SO 2− 4. [4] From the ionic molar conductivities of cations and anions, effective ionic radii can be calculated using the concept of Stokes radius.
Charge carrier density, also known as carrier concentration, denotes the number of charge carriers per volume. In SI units, it is measured in m −3. As with any density, in principle it can depend on position. However, usually carrier concentration is given as a single number, and represents the average carrier density over the whole material.