Pr
o
Minent
®
27
Fault
The sensor
cannot be
calibrated -
measuring
device/
controller
display value is
greater
than
DPD-1
measurement
The sensor
cannot be
calibrated -
measuring
device/
controller
display value is
smaller
than
DPD-1
measurement
Measured
variable value
is “zero”
Measured
variable display
unstable
Remedy
왘
See 7.1 “Run-in period”
왘
Replace membrane 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 7.1 “Run-in period”
왘
Remove deposits (see 9
“Servicing”). Replace membrane
cap. Run-in sensor, calibrate
왘
Increase flow (see 15 “Technical
Data”)
왘
Tap to remove air bubbles and
increase flow if necessary
왘
Return sensor to ProMinent
왘
Add new electrolyte (see 5
“Assembly”, 7.1 “Run-in Period”
and 7.2 “Calibration”)
왘
Discuss with ProMinent
왘
Identify contaminant and replace
water if necessary
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 necessary
왘
Replace membrane cap. Run-in
sensor, calibrate
왘
Identify cause and remedy
Possible cause
Run-in period too short
Membrane cap damaged
Interference from water
contaminants (see 15 “Technical
Data”, “Cross-Sensitivity”)
Short circuit in signal cable
Outdated DPD chemicals
Run-in period too short
Membrane cap deposits
Sample water flow inadequate
Air bubbles on the outside of the
membrane
Reference electrode spent (shiny
patches appearing)
No electrolyte in membrane cap
Electrolyte is penetrating sample
water via gas bubbles
Interference from water
contaminant (see 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
membrane
Membrane damaged
Cause lies with the controller
Troubleshooting
8
Troubleshooting
BA_DT_099_10_08_4spr.p65
13.10.2008, 10:39 Uhr
27