Conductivity Measurement; Measuring Ranges And Cell Constants - Tintometer Lovibond SD 325 Con Mode D'emploi

5 Conductivity measurement

5.1 Measuring ranges and cell constants

Depending on the type of electrode, various measuring ranges are accessible. In the configu-
ration menu, 4 possible cell constant ranges (CELL rAnG) can be set for various electrodes.
From the multiplication with one factor (CELL FACt = 0.3800 ... 1.500), the cell constant K
specific to one electrode can be set.
Cell constant range / CELL
rAnG
0.01
0.1
1
10
The setting of the cell constant via the configuration menu is useful if specified in the
case of a new purchase from the manufacturer. Information regarding factory-tes-
ted cell constants can be found in the test log or on the cable tag on the electrode.
Alternatively, the cell constant can be determined via calibration (alignment function) either
using the automatic recognition of a standard reference solution or the manual entry of
a known conduction value.
5.2 Cell constant alignment (calibration) of the conductivity electrode
If used correctly, the standard electrodes remain stable over time. Using the integrated
CAL function, the original cell constant can be checked for changes. The cell constant
may differ, for example due to contamination on or damage to the surface of the original
cell constant. Alignment of the cell constant clarifies the current state of the measuring
cell and contributes to the assessment of whether it needs to be cleaned or replaced.
Please note the following instrument settings before starting the alignment function:
• Ensure that the parameter Con ( ) is selected in the display.
• In the configuration menu, set whether an automatic cell constant alignment is to take place
with a standard reference solution (REF.S) or by means of the manual entry of a solution
value (Edit) (<SEt PArA>: CAL)
• If necessary, select the required standard reference solution (<SEt PArA>: REF.S)
54
Cell constant K = CELL rAnG * CELL FACt
Adjustable cell constant
K / 1*cm
0.003800–0.015000
0.03800–0.15000
0.3800–1.5000
3.800–15.000
Examples of use
-1
e.g. ultrapure water
electrodes with
K ≈ 0.01
e.g. ultrapure water
electrodes with K ≈ 0.1
e.g. standard electro-
des with K ≈ 0.55,
K ≈ 0.42, K ≈ 1
e.g. electrodes with
K ≈ 10 (for high
conductivities)
SD_325_Con_1 06/2020