Xylem ProLab 4000 MULTIPARAMETER BENCHTOP METER - Manual (Page 136)

Conductivity ProLab 4000
136 ba75646d02 01/2010
10.2.4 Determining/setting the temperature compensation
The conductivity of aqueous solutions is mainly caused by the temper-
ature and the concentration of dissolved substances.
Reference temperature To compare measured values that were determined at different tem-
peratures they have to be converted to a reference temperature. Thus,
a conductivity specification includes a reference temperature specifica-
tion as a matter of principle.
Temperature compensa-
tion
The temperature compensation is used to calculate the conductivity at
the reference temperature from a conductivity value that was measured
at any temperature.
To do so, the temperature dependency (linear or nonlinear) of the con-
ductivity for the solution must be known.
The characteristics of the test sample indicate which procedure is suit-
able for temperature compensation.
For diluted test samples, linear and nonlinear temperature dependen-
cies are stored in the meter.
For other test samples the ProLab 4000 provides the option of deter-
mining the temperature dependency and, if necessary, the concentra-
tion dependency of the conductivity as well.
Characteristics of the test samples Procedure for temperature
compensation
z diluted
z wide temperature range
nonlinear (TC nLF)
z diluted
z small temperature range linear (TC lin)
z concentrated
z wide temperature range nonlinear (TC nLin1...2)
z wide concentration range
z wide temperature range nonlinear (
TC nLin3, TC nLin4)