Troubleshooting - ProMinent DULCOTEST BRE 1-mA-10 ppm Mode D'emploi

Troubleshooting

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
photometric method. If necessary, repeat the DPD measurement several
times.
Fault
Sensor can not be calibrated:
Measured value higher than
DPD-measurement
42
1) Measurement/control device
2) Electrical leads and connectors
3) In-line probe housing and hydraulic connections
4) Sensor
a) Bromine concentration 0.2 - 10 mg/l
b) Constant pH in the range 6.5 - 9.5
c) Constant temperature in the range 4 - 45 °C
d) Conductivity: 0.03 - 40 mS/cm
e) Flow: 20 - 100 l/h
®
D1C, Bromine.
Possible Cause
1) It was calibrated with DPD 1
in presence of organically bound
bromine as disinfectant e.g.
BCDMH
2) Run-in time too short
3) Membrane cap damaged
4) Interfering substances in sample
water (see "cross sensitivity" in
Chapter 14, Technical data)
5) Short -circuit in signal lead
6) Distance between working
electrode and membrane too great
7) DPD chemicals spent
8) pH-value < pH 6.5
® Simulator order no. 1004042) is
Action
Calibrate sensor with DPD 4
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
Raise pH-value (6.5-9.5)
®
ProMinent