Xylem ProLab 4000 - Manual (Page 118)

Ion concentration ProLab 4000
118 ba75646e03 12/2012
9.6.3 Double standard addition
In the Double standard addition procedure, a known amount of stan-
dard solution is added to the sample in two steps.
First, one percent of the sample volume is added, then 2 percent of the
sample volume is added.
The ion concentration in the sample is calculated from the change in
potential between the first and second addition of standard solution.
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, Dou-
ble standard addition.
The ISE method: The Double standard addition window pops
up.
The Sample register is open.
3 In the Sample register, enter the values for the sample volume
(Sample volume) and the volume of the ISA/TISAB solution
(ISA/TISAB volume) as necessary.
4 Use [Dosing] to automatically add the adjusted volume of the
ISA/TISAB solution (ISA/TISAB volume).
or
If the burette control is inactive:
Add the adjusted volume of the ISA/TISAB solution (ISA/TISAB
volume) manually.