ELMETRON CX-401, User Manual, Page: 56 / 120

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User‘s manual for CX-401 multifunction meter v6.0x
To calibrate:
-
in the measuring mode press the button until the screen with the cell
number ( , , ) and the K constant value displays (Pic. 28.). The
symbol next to the K constant value corresponds to entering thew K
constant manually. If calibration in standard solutions has been made
earlier, than in the place of K constant value lines will be displayed;
- with the , buttons choose the cell number ( , , );
-
press and hold the button, until the CAL symbol appears on the
display;
-
with the , buttons enter the K constant value;
- press the button and return to the mode of choosing the cell number
or enter the measuring mode by pressing the button.
Pic. 28.
15.2. Calibration with use of standard solutions
Calibration is made in order to determine the K constant of the cell. The
meter enables 5-point calibration in standard solutions of freely chosen
value. In case of 1-point calibration it is advisable to use a standard of value
close to the anticipated value of the measured solution. Calibration requires
high-quality standard solutions to be used. Calibration is made in currently
chosen measurement unit (section 13.1).
It is necessary to comply with the principles given below to obtain the exact
results of calibration:
1. In case of calibration in more than one point first use the standard of
the lowest conductivity value and finish with the solution of the highest
conductivity value.
2. The temperature of the standard solution should be equal to the
reference temperature (most often it is 25
0
C), it is advisable to use a
thermostat.
3. New, unused standard solution should be applied.
4. The cell and its electrodes should be clean and devoid of bubble of air.
5. The cell should be placed in an electrode holder.