Endress+Hauser Mycom CLM 152 Operating Instructions Manual page 61

Mycom CLM 152
9.2.2 Determining the cell constant
Measure the conductivity of a calibration
solution (of precisely known conductivity)
(see Chap. 3.7.2):
When you set the display to the conductivity
of the calibration solution, the instrument
then calculates the cell constant.
Proceed as follows:
• Select the sensor you want to calibrate
(only for differential measurements)
• Clean the sensor
• Place the sensor and, if necessary, the
temperature sensor in the calibration
solution
• Start the calibration by pressing »E«
⇒ The measured value of the calibration
solution is displayed
Note:
To carry out a high-precision
calibration, the temperature
influence of the temperature
difference in relation to the reference
temperature must be eliminated, i.e.
calibration must take place at the
reference temperature. If this is not
possible, you can enter the
calibration temperature and the Tc
value of the calibration solution in
the »Instrument data / Calibration«
menu.
Function
Select sensor (not for single-circuit)
Message
Display conductivity of calibration
solution
current Tc, temperature
Enter setpoint of calibration solution
Display cell constant
Calibrate
Continued on next page
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• Wait until the measured value stabilises
• Accept the measured value by pressing
»E«
• Set the precise value of the calibration
solution by pressing the arrow keys
• Confirm the input by pressing »E«
⇒ The calculated cell constant is displayed
• End the calibration or repeat the procedure
If you select »End cal.«, the cell constant just
calculated is accepted and the system then
switches to Measuring mode.
Note:
To measure the precise
temperature, the temperature sensor
must be checked and, if necessary,
calibrated in the »Instrument data /
Temperature«menu every time
before the conductivity
measurement is calibrated.
Selection
Sensor 1
Sensor 2
0 µS/cm ... 1000 mS/cm
End Cal.
Repeat Cal.
Cal. channel 2 (only for difference)
Calibration
Default
Sensor 1
Clean sensor
and place in
calibration
solution
current
measured value
x.xxx 1/cm
End Cal.
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