
Pr
o
Minent
®
26
Troubleshooting
Fault
The sensor
cannot be
calibrated -
meter/
controller
display value is
greater
than
DPD-1
measurement
The sensor
cannot be
calibrated -
meter/
controller
display value is
smaller
than
DPD-1
measurement
Measuring
value readout
is “Zero”
Measuring
value readout
unstable
Remedy
왘
See section 7.1 “Run-in Period”
왘
Replace diaphragm cap. Run-in
sensor, calibrate
왘
Identify interfering contaminant and
implement remedy
왘
Identify short circuit and repair
왘
Use new DPD chemicals, repeat
calibration
왘
See section 7.1 “Run-in Period”
왘
Remove deposits (see section 9
“Maintenance”). Replace diaphragm
cap. Run-in sensor, calibrate
왘
Increase sample water flow (see
section 15 “Technical Data”)
왘
Tap to remove air bubbles and
increase flow if necessary
왘
Return sensor to ProMinent
왘
Remove surfactant and replace
diaphragm cap. Run-in sensor,
calibrate; use CDP sensor
왘
Add new electrolyte (see sections 5
“Assembly”, 7.1 “Run-in Period”
and 7.2 “Calibration”)
왘
Discuss with ProMinent
왘
Identify interfering contaminant and
if necessary replace water
왘
Add ClO
2
and then repeat
calibration or use appropriate
sensor
왘
Connect sensor correctly to
controller
왘
Tap to remove air bubbles and
increase flow if neccessary
왘
Replace diaphragm cap. Run-in
sensor, calibrate
왘
Identify cause and remedy
Possible cause
Run-in period too short
Diaphragm cap damaged
Interference from water
contaminant (see section 15
“Technical Data”, cross-sensitivity)
Short circuit in signal cable
DPD chemicals spent
Run-in period too short
Diaphragm cap deposits
Sample water flow inadequate
Air bubbles on the outside of the
diaphragm
Reference electrode spent (shiny
patches showing)
Surfactant in water (diaphragm is
translucent)
No electrolyte in diaphragm cap
Electrolyte is penetrating sample
water via gas bubbles
Interference from water
contaminant (see section 15
“Technical Data”, cross-sensitivity)
ClO
2
content below the lower
measuring range limit
Sensor incorrectly connected to
controller
Air bubbles on the outside of the
diaphragm
Diaphragm damaged
Cause lies with the controller
8
Troubleshooting
BA_DT_095_08_08_4spr.p65
05.08.2008, 12:42 Uhr
26