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Operation
It is recommended to recalibrate after 24 h of functioning and after that verify the system
periodically.
4.10.3.1 Calibration at a reference value
Readjustment of the measured value. A previously a measurement of the free residual
chlorine in the sample should be done by DPD1.
Calibration is performed in one point, it is not necessary to do adjustment at 0.
1. From the main menu select CALIBRATE. Confirm.
2. Select the channel to calibrate and confirm.
3. Select CAL. REFERENCE VALUE and confirm.
Note: The calibration at a reference value does not provoke any change in the relays and 4-20 mA
output stage.
4. Adjust the measured value using the keypad.
5. Press OK to accept calibration.
4.10.3.2 Reset calibration
It erases the calibration data in memory and returns to the calibration data from factory.
1. From the main menu select CALIBRATE. Confirm.
2. Select the channel and confirm.
3. Select RESET CALIBRATION and confirm.
Note: To measure is indispensable performing a calibration against DPD-1. The factory calibration
does not provoke any change in the relays and 4-20 mA output stage.
4.10.4 Measurement
The display shows the chlorine concentration value in ppm measured with the sensor 60
70. If a temperature probe Pt 1000 is connected to the instrument, the display will also
show the temperature.
Temperature readjustment, see detailed information on 4.16, Page 54.
4.10.5 Amperometric sensor
It is a potentiostatic, membrane sensor with 3 electrodes.
The chlorine diffuses through the membrane, reacts with the electrolyte and generates an
electrical signal at the measuring electrode. This electrical signal is proportional to the
chlorine concentration. The measurement is independent from the temperature of the
samples thanks to an integrated temperature compensation. Only the free residual
chlorine is measured.
Electrode installation, refer to Figure 24, Page 43
1. Unscrew the membrane from the electrode.
2. Refill the membrane up to the edge with the enclosed electrolyte. Ensure that there
are not air bubbles.
3. Move the silicone O-ring ensuring that the hole for electrolyte outlet is open.
4. Screw the membrane on the electrode. The excess of electrolyte will go out from the
outlet hole.
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