NAVI D-25, Инструкция по эксплуатации

Страница: 202 / 227

7 Reference
7.4 Conductivity measurement
D-52/53/54/55 191
●
Measuring conductivity
“Conductivity” is an index that expresses the ease with
which electric current flows through a material.
Conductors are categorized either as “electron
conductors” (such as metals and other substances
which use free electrons to conduct electricity) or “ion
conductors” (such as electrolytic solution or fused salt,
which use ions to conduct electricity). This section deals
with the kind of conductivity that pertains to ions,
especially the conductivity of electrolytic solution that
uses water as the solvent. As shown in Fig. 3, two pole
plates with an area A (expressed in m
2
) are positioned
parallel to each other, separated by distance l
(expressed in m). Then solution is poured into the cell
until it is full and alternating current is run between the
plates.
Fig. 3 Conductivity cell example
Each positive and negative ION in the solution will
migrate toward the oppositely charged pole. The result is
that current flows through the solution by means of ION
conductivity. When this occurs, resistance R (expressed
Solution
Polar plates a m
2
x2