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
ð
As an immediate measure, you can
remove the air bubbles by knocking
against the flow gauge housing.
3.
Check whether the electrodes are dirty/
soiled
ð
If yes, then clean the sensor
4.
Is the chlorine concentration outside of
the measuring range indicated on the
sensor?
ð
If yes, reduce the chlorine concen‐
tration until it is within the measuring
range and then clean the sensor
5.
Clarify whether there might be trouble‐
some substances (e.g. tensides/oils) in
the sample water
ð
If there are then contact ProMinent.
6.
Check whether the conductivity of the
water is at least 50μS/cm
ð
Type CLO sensors cannot be used
in completely desalinated water.
7.
Check whether there is cyanuric acid in
the water (e.g. using the DT 1 photo‐
meter)
NOTICE!
Cyanuric acid
Cyanuric acid is often contained in
chlorine tablets; never use any
chlorine tablets if you want to use
type CLO sensors.
ð
If there is cyanuric acid in the water
then sensor types CLO 1 and CLO 2
cannot be used. Contact ProMinent.
8.
Check the age of your DPD chemicals
ð
If there is doubt, repeat the DPD
measurement with new chemicals
and then re-calibrate.
9.
When directly connecting the sensor to
external devices (e.g. PLC), make sure
that the sensor is galvanically isolated
from all other devices/consumers
ð
Always use a separating transformer
for the supply.
10.
Foreign (stray) potentials on the water
(e.g. due to defective rotary pump)
11.
If the reason for this disturbance cannot
be determined we recommend you clean
Troubleshooting
27
