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ec_theory [31/03/2015 09:47] pieter |
ec_theory [11/04/2018 11:49] pieter |
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The basic unit of resistance is the familiar Ω (Ohm). Conductance is the reciprocal of resistance, and its basic unit is the Siemens (S). In discussions of bulk material, it is convenient to talk of its specific conductance, | The basic unit of resistance is the familiar Ω (Ohm). Conductance is the reciprocal of resistance, and its basic unit is the Siemens (S). In discussions of bulk material, it is convenient to talk of its specific conductance, | ||
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Users of ultra pure water prefer to use the resistivity unit of //MΩ.cm//, because the measurement in this unit tend to spread the scale out in the range of interest. These same users frequently use //kΩ.cm// when dealing with less pure water such as tap water. | Users of ultra pure water prefer to use the resistivity unit of //MΩ.cm//, because the measurement in this unit tend to spread the scale out in the range of interest. These same users frequently use //kΩ.cm// when dealing with less pure water such as tap water. | ||
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Since the conductivity of a solution varies with temperature, | Since the conductivity of a solution varies with temperature, | ||
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**G = C x cc / (1 + a(t -tr))** | **G = C x cc / (1 + a(t -tr))** | ||
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in which: | in which: |