Troubleshooting - ProMinent DULCOTEST CLT 1 Mode D'emploi

10 Troubleshooting

Troubleshooting must take account of the whole measuring system. The
measuring system consists of (see fig. 2)
The possible causes of failure listed in the following table primarily refer
to the sensor. Before commencing troubleshooting please ensure that the
operating conditions in "Technical data", Chapter 14 are met:
The sensor simulator (DULCOMETER
recommended for locating a controller malfunction. You will find a detailed
description of troubleshooting of the controller in the operating instructions
of DULCOMETER
If the value measured by the sensor differs significantly from that of the DPD
method you need to first consider all possible malfunctions of the DPD photo-
metric method. If necessary, repeat the DPD measurement several times.
Fault
Sensor can not be calibrated:
Measured value higher than
DPD-measurement
Sensor can not be calibrated:
Measured value lower than
DPD-measurement
®
ProMinent
1) Measurement/control device
2) Electrical leads and connectors
3) In-line probe housing and hydraulic connections
4) Sensor
a) Chlorite content 0.1 - 2 mg/l resp. 0.02 - 0.5 mg/l
b) Constant pH in the range 6.5 - 9.5
c) Temperature 1 - 40 °C, no sudden rises in temperature
d) Conductivity: 0.05 - 5 mS/cm
e) Flow: 20 - 100 l/h
®
D1C, Chlorite.
Possible Cause
1) Run-in time too short
2) Membrane cap damaged
3) Interfering substances in sample
water (see "cross sensitivity" in
Chapter 14, Technical data)
4) Short -circuit in signal lead
5) Distance between working
electrode and membrane too great
6) DPD chemicals spent
1) Run-in time too short
2) Built-up of deposits on
membrane cap
Troubleshooting
® Simulator order no. 1004042) is
Action
See Chapter 8.1 "Run-in period"
Replace membrane cap, run in
sensor and calibrate
(see chapter 6, 8.1, 8.2)
Examine sample water for
interfering substances and remedy
Locate and eliminate short circuit
Screw the membrane cap tightly
onto the electrode shaft, so that
no gap can be seen anymore
Use new DPD chemicals, repeat
calibration
See Chapter 8.1 "Run-in period"
Replace membrane cap (see
Chapters 6, 8.1 "Run-in period"
and 8.2 "Calibration")
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