wtw Cond 7110 - Glossary of Terms; Conductivity Terms

Glossary Cond 7110
38 ba75927e03 04/2012
11 Glossary
11.1 Conductivity
Specialist
term
Description
Cell constant,
C
Characteristic quantity of a conductivity measuring cell,
depending on the geometry.
Conductivity Short form of the expression, specific electrical conductiv-
ity. It corresponds to the reciprocal value of the resistivity.
It is a measured value of the ability of a substance to con-
duct an electric current. In water analysis, the electrical
conductivity is a dimension for the ionized substances in a
solution.
Reference
temperature
Fixed temperature value to compare temperature-depen-
dent measured values. For conductivity measurements,
the measured value is converted to a conductivity value at
a reference temperature of 20 °C or 25 °C.
Resistance Short name for the electrolytic resistivity. It corresponds to
the reciprocal value of the electrical conductivity.
Salinity The absolute salinity S
A
of seawater corresponds to the
relationship of the mass of dissolved salts to the mass of
the solution (in g/kg). In practice, this dimension cannot be
measured directly. Therefore, the practical salinity accord-
ing to IOT is used for oceanographic monitoring. It is
determined by measuring the electrical conductivity.
Salt content General designation for the quantity of salt dissolved in
water.
Temperature
coefficient
Value of the slope of a linear temperature function
Temperature
compensation
Name of a function that considers the temperature influ-
ence on the measurement and converts it accordingly.
Depending on the measured parameter to be determined,
the temperature compensation functions in different ways.
For conductimetric measurements, the measured value is
converted to a defined reference temperature. For potenti-
ometric measurements, the slope value is adjusted to the
temperature of the test sample but the measured value is
not converted.
T
Ref
=
Meas
*
1
1+
a
(T - )
*
T
Ref