ProMinent DULCOTEST CLT 1-mA-2 ppm Montage- Und Betriebsanleitung Seite 26

Information on Troubleshooting and Fault Elimination
Error Possible cause
DPD chemicals out of date.
pH value < pH 5.5.
Sensor cannot be Run in period too short.
calibrated and
Deposits on the diaphragm cap.
the measured
value of the
sensor less than
Sample water flow rate too low.
the DPD meas‐
urement.
Air bubbles on the outside of the
diaphragm.
pH value > pH 9.5.
No electrolyte in diaphragm cap.
Electrolyte pushed out by gas bub‐
bles in the sample water.
Troublesome substances in the
sample water (surfactants, oils,
alcohols, corrosion-inhibitors).
Measured value Measuring line broken
„0" .
display is
Sensor connected to the controller
with incorrect polarity.
Run in period too short.
Sensor faulty.
Sensor meas‐ Interfering substances in sample
ured value is 0 water, e.g. reducing compounds.
ppm and sensor
Run in period too short.
current is 3.0 ...
4.0 mA.
Sensor faulty.
Controller limit Check system (actual chlorite con‐
value monitoring centration, flow, control parame‐
for current limit ters, size of actuator etc.).
value (20 mA)
The power supply is weak (when
has been trig‐
the measuring range is occasion‐
gered. Sensor
ally exceeded).
measured value
is OK - the
Sensor measuring range is too low
chlorine concen‐
(when the measuring range is fre‐
tration was only
quently exceeded).
briefly too high.
26
Remedy
Use new DPD chemicals, repeat calibra‐
tion.
Increase pH value (pH 5.5 ... 9.5).
Observe the run in period.
Replace diaphragm cap; allow sensor to
run in and calibrate.
Correct flow rate.
Increase the flow within the permitted
range.
Lower pH value (pH 5.5 ... 9.5).
Fill with new electrolyte.
Contact ProMinent.
Replace measuring line.
Connect the sensor correctly to the con‐
troller.
Observe the run in period.
Return sensor for regeneration.
Contact ProMinent.
Observe the run in period.
Return sensor for regeneration.
Correcting faults located.
Use a stronger power supply, refer to
"Technical Data".
Use a sensor with suitable measuring
range.