ELMETRON CC- 411, User Manual, Page: 24 / 52

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User’s manual for CC-411 conductivity meter v5.30
9. CALIBRATION OF THE CONDUCTIVITY CELL
Characteristic feature of every conductivity cell is its K constant. Before
displaying the result on the display the value is multiplied by the K constant
value. The value of the K constant depends on the size of the electrodes’
surface and the distance between them. If the user keeps the cell clean, the
K constant does not change.
In case of contamination of the surface of the
electrodes, the K constant will change.
Calibration may be performed without the sample solution, by entering the
value of the K constant of the cell given by the manufacturer to the meter’s
memory (we recommend this kind of calibration) or with use of standard
solution with known conductivity, to determine the K constant.
The K constant is precisely determined by the cell manufacturer and
using this value will be the most reliable.
In case of calibration performed by the user, fresh, accurately prepared
standard solution is required. Additionally it has to be accurately
thermostatic to 25
0
C. If the conditions won‘t be kept the calibration may
be burdened with error.
9.1. Calibration without the standard solution
The meter has a possibility of calibration without the use of standard solution.
For such calibration, it is necessary to know the K constant of the conductivity
cell. This value may be given by the cell manufacturer or may be determined
using the
CC-411 meter after calibrating it in the standard solution.
In order to calibrate:
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in the conductivity measuring mode press the button till the moment
of displaying the symbol in the bottom row and the k symbols and
the value of the K constant introduced earlier in the upper row.
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with the , buttons enter the value of the K constant;
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return to the measuring mode by pressing and holding the
button.
Pic. 7