Pr
o
Minent
®
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pH/Chlorine Dioxide
8.11.4
DULCOMETER
®
D2C Measured Variable pH/Chlorine Dioxide,
DULCOTEST
®
CDE Chlorine Dioxide Sensor and DULCOTEST
®
Sensor
PHEP or PHER for pH, Maintenance
Controller
The
DULCOMETER
®
controller type D2C for the measured variable pH/chlorine dioxide is
main te nance-free.
Sensor
DULCOTEST
®
CDE Chlorine Dioxide Sensor
IMPORTANT
• The sensor must be regularly serviced in order to avoid overdosing due to sensor failure!
• Observe applicable national directives for servicing intervals!
• Do not touch the electrodes or bring them into contact with greasy substances!
Maintenance interval
Daily/weekly servicing intervals depending upon application.
Maintenance
Work
Check the sensor display value at the controller using an appropriate chlorine dioxide
meas ur ing system (e.g. DPD-1).
Recalibrate the sensor if necessary.
Cleaning the Membrane
If the membrane is dirty and is preventing calibration of the sensor you can try to clean the
diaphragm gently.
First dismantle the sensor as described in the sensor dismantling section. Observe safety
guidelines! Removal of surface contamination.
Rinse the membrane under a gentle stream of cold water.
Removal of Lime Deposits
Place the membrane cap in 1 % hydrochloric acid (e. g. overnight).
Rinse the membrane cap with plenty of water.
Now
fi ll the sensor with electrolyte, run in and recalibrate.
Replacing the Membrane
If calibration is no longer possible after cleaning the membrane, or if the membrane is damaged it
must be replaced.
Sensor
DULCOTEST
®
PHEP or PHER for pH
IMPORTANT
The sensor is to be regularly serviced to avoid any excess metering caused by a sensor
failure!
Observe the valid national regulations for maintenance intervals!
Do not touch the electrodes or bring into contact with greasy substances!
Maintenance interval
monthly
Maintenance
Work
The sensor should regularly (once a month) undergo a visual check and be cleaned if necessary.
If deposits on the glass electrode withstand cleaning with a soft, moistened cloth, the following
cleaning agents may be used:
Kind of deposit
Agent and duration of application
General deposits
Non-abrasive household cleaner
Scale or metal hydroxides
Diluted hydrochloric acid (approx. 0.1-3 %, 1-5 minutes)
Oil, grease
Solvents, like alcohol or acetone
Biofouling
Mixture of diluted hydrochloric acid and pepsin, several hours
Solvents (e.g. acetone) must not be used to clean electrodes as
they can demage the plastic stems.
It is essential that the probes are rinsed thoroughly after having been cleaned.
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