ALTANA LC 4 - Manual (Page 21)

BYK LC 4 Operation
21
4.4 Adjusting/calibrating the cell constant
Why adjust/
calibrate the cell
constant?
The actual cell constant of the sensor module can slightly differ from the
nominal value of the cell constant.
Depending on the required measuring accuracy, you can measure with the
nominal value of the cell constant that was set in the factory (see chapter
7 T
ECHNICAL DATA ), or adjust the value of the cell constant.
You have the following options to adjust the value of the cell constant:
! (Determining and) Adjusting the cell constant manually
The cell constant can be adjusted in the following ranges:
! Calibrating the cell constant (automatic determination)
This method can be selected for the TetraCon V sensor module (range
that can be calibrated: 0.450 ... 0.500 cm
-1
).
Calibration is carried out in the 0.01 mol/l KCl control standard.
Cell constants outside the above mentioned ranges cannot be adjusted or
calibrated.
Both the calibration data and the value of the manually adjusted cell constant
are stored in the sensor module and can be selected and used for measure-
ments.
Note
Aging slightly changes the characteristics of the cell, e. g. by coatings. As a
result, an inexact measured value is displayed. The original characteristics of
the cell can often be restored by cleaning the cell.
When to adjust/
calibrate the cell
constant?
! If the measuring accuracy with the nominal value of the cell constant that
was set in the factory does not suffice (see chapter 7 T ECHNICAL DATA )
! After the calibration interval has expired (when the sensor symbol flashes)
Calibration interval The interval for the determination of the cell constant is set to 180 days in the
factory. You can select the interval in the range of 1 ... 999 days (see section
4.8).
You should calibrate at regular intervals (we recommend: every 6 months).
– TetraCon V 0.450 ... 0.500 cm
-1