Xylem ProLab 4000 MULTIPARAMETER BENCHTOP METER - Manual (Page 114)

Ion concentration ProLab 4000
114 ba75646e02 01/2010
9.6.2 Standard addition
In the Standard addition procedure, a known amount of standard solu-
tion is added to the sample.
The ion concentration in the sample is calculated from the change in
potential.
Calibration
Measuring
1 Check the currently displayed ion.
If the ion to be measured is displayed incorrectly:
Select the ion type in the menu, Measuring / ISE methods / Ion
type.
2 In the Measuring / ISE methods menu, select the method,
Standard addition.
The ISE standard input window for the first calibration standard
appears.
3 Carry out a two-point calibration according to the user guid-
ance (see page 106).
As soon as a stable value is achieved for the second standard
calibration solution, the slope (mV) and evaluation (Error, +++)
of the electrode after calibration is displayed.
The infotext, Accept calibration and terminate is displayed.
4 Using [OK], confirm the infotext Accept calibration and termi-
nate.
The calibration record is displayed and output to the interface.
The calibration procedure is finished.
5 Close the calibration record with [OK].
The ISE method: The Standard addition window pops up. The
Sample register is displayed.