ProMinent DULCOTEST CLO 1 Guide D'utilisation page 30

Troubleshooting
Error description:
Sensor display >> DPD 1 value,
No calibration possible (gradient too high)
Measure/Remedy
1. Check whether there is additional
oxidising agent (e.g ozone, chlorine
dioxide, or chloramines) in the
sample water
ð Remove them. If this is not pos‐
sible then contact ProMinent.
2. Check the age of your DPD chemi‐
cals
ð If there is doubt, repeat the
DPD measurement with new
chemicals and then re-cali‐
brate.
3. 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 trans‐
former for the supply.
4. Foreign (stray) potentials on the
water (e.g. due to defective rotary
pump)
5. If the reason for this disturbance
cannot be determined we recom‐
mend you clean the sensor as
described in
Ä further information on page 33 .
30
Error description:
Sensor display fluctuates
Fluctuation due to system
Repeat the DPD measurement at
short intervals and thereby exclude
that the sensor fluctuations are not
caused by the system.
Measure/Remedy
1. Check that there is a constant flow
rate at the sensor of at least 30 l/h .
2. Make sure that there is a sufficient
mixing distance after metering the
chlorine .
ð If necessary, install a static
mixer.
3. 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 trans‐
former for the supply.
4. Foreign (stray) potentials on the
water (e.g. due to defective rotary
pump)