Error description:
Sensor display << DPD 1 value
No calibration possible (gradient too low)
Measure/Remedy
1.
Check that the flow rate at the sensor is
at least 30 l/h
2.
Check whether there are air bubbles on
the electrodes. If yes then the flow rate
must be increased through the flow
gauge housing
As an immediate measure, you can
ð
remove the air bubbles by knocking
against the flow gauge housing.
3.
Check whether the electrodes are dirty/
soiled
If yes, then clean the sensor
ð
on page 31 as described.
4.
Is the chlorine concentration outside of
the measuring range indicated on the
sensor?
If yes, reduce the chlorine concen‐
ð
tration until it is within the measuring
range and then clean the sensor
on page 31 as described.
5.
Clarify whether there might be trouble‐
some substances (e.g. tensides/oils) in
the sample water
If there are then contact ProMinent.
ð
6.
Check whether the conductivity of the
water is at least 50μS/cm
Type CLO sensors cannot be used
ð
in completely desalinated water.
7.
Check whether there is cyanuric acid in
the water (e.g. using the DT 1 photo‐
meter)
ð
8.
Check the age of your DPD chemicals
ð
9.
When directly connecting the sensor to
Ä
external devices (e.g. PLC), make sure
that the sensor is galvanically isolated
from all other devices/consumers
ð
10.
Foreign (stray) potentials on the water
(e.g. due to defective rotary pump)
Ä
11.
If the reason for this disturbance cannot
be determined we recommend you clean
the sensor as described in
on page 31 .
Troubleshooting
NOTICE!
Cyanuric acid
Cyanuric acid is often contained in
chlorine tablets; never use any
chlorine tablets if you want to use
type CLO sensors.
If there is cyanuric acid in the water
then sensor types CLO 1 and CLO 2
cannot be used. Contact ProMinent.
If there is doubt, repeat the DPD
measurement with new chemicals
and then re-calibrate.
Always use a separating transformer
for the supply.
Ä
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