In-Situ Aqua TROLL 100 and 200 Operators Manual - Manual (Page 47)

Page 47 Aqua TROLL Operator’s Manual
5 Conductivity
About Conductivity
Conductivity measures the ability of a material to carry an
electric current. Generally, the higher the concentration of
dissolved salts and minerals in water, the better the water is
as a conductor, therefore the electrical conductivity is higher.
Deionized/distilled water is a poor conductor because almost
all anions and cations are removed during the deionization/
distillation process.
If conductivity changes in a body of water, it often indicates an
environmental event. For example, a dramatic increase in the
electrical conductivity of an underground fresh water aquifer
located near the ocean could indicate the beginning of saltwater
intrusion. On the other hand, an increase in the electrical
conductivity of a small lake that is completely surrounded
by farmland may simply be the result of runoff from recent
precipitation.
How is Conductivity Measured?
Conductance is the reciprocal of the resistance, in ohms,
measured between two opposing electrodes of a 1 cm cube at
a specific temperature. The unit 1/ohm or mho was given the
name of Siemens (S) for conductance. It is not practical to require
all conductance cells to have the dimensions of an exact cube. To