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13.5 Fault finding chart
Observe the installation and operating
Caution
instructions of the measuring amplifier and
controller!
Fault
1. No display.
No electricity supply to
the measuring cell.
2. The measured value is
lower than the reference
measurement.
3. The measured value is
higher than the reference
measurement.
4. The measured value is
unstable.
Cause
a) A disinfection or oxidation agent is missing in
sample water.
b) The electrode cable connection is interrupted.
c) No or too low sample water flow rate.
d) The measuring electrodes are faulty.
e) The measuring electrodes are contaminated or
made passive by deposits.
a) The measuring electrodes are faulty.
b) The measuring electrodes are contaminated or
made passive by deposits.
c) The temperature has fallen since the calibration.
d) The system has run too short time prior to
calibration.
e) Unsuitable chlorination agent.
f)
Incorrect photometric reference measurement
during calibration.
g) The pH value for the chlorine measurement has
risen since the calibration.
h) The quantity of sample water is set too low.
i)
The cleaning wing is blocked.
a) The temperature has risen since the calibration.
b) The pH value for the chlorine measurement has
fallen since the calibration.
c) Interference by other oxidation agents in the
sample water.
a) Interferences on the signal lines.
b) The reference electrode diaphragm is blocked.
c) The measuring electrode is contaminated or faulty. Clean the measuring electrode using a diluted
d) The filter is contaminated, and the quantity of
sample water is therefore too low.
e) Siphon effect at the sample water outlet.
Remedy
Check the concentration by making a reference
measurement. Check the dosing units, and
activate dosing. Check the settings of the
measuring amplifier.
Remake the connection. Replace damaged
cables.
Clean the filter, check the flow rate, and check
the sample water inlet pressure.
Replace the measuring electrode.
Dismantle, clean or replace the measuring
electrode.
Replace the measuring electrode.
Remove, clean or replace the measuring
electrode.
Recalibrate. Activate the automatic temperature
compensation, where applicable.
Let the system run for at least two hours, and
recalibrate.
Only use chlorine solutions such as chloric gas,
sodium hypchlorite and chlorinated lime. Do not
use organic products such as trichlorine
isocyanic acid, as these cannot be measured if
this procedure is used.
Check the reference
measurement,
another measurement. Repeat the calibration.
Keep the pH value constant. Recalibrate.
Activate the pH value compensation.
Check and set the quantity of sample water.
Check the filter, and clean it, if necessary.
Fit the cleaning wing correctly.
Recalibrate. Activate the automatic temperature
compensation.
Keep the pH value constant. Recalibrate.
Activate the pH value compensation, where
applicable.
Analyse the sample water. Check the chemicals
used.
Check the screen and the connections to the
amplifier.
Clean the diaphragm (on the side at the bottom
of the reference electrode) using diluted
hydrochloric acid (10 %). Replace the reference
electrode, if necessary.
abrasive cleaning agent. Replace the measuring
electrode, if necessary.
Check the filter, and clean it, if necessary.
Ensure a flow of sample water with no
counter-pressure.
and take
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