Ph Diagnostics - ABB AWT420 Operating Instruction

AW T4 2 0 | U N I V E R S A L 4 - W I R E , D U A L- I N P U T T R A N S M I T T E R | O I/A W T4 2 0 - E N R E V. B

pH diagnostics

NAMUR Diagnostic
icon message
S(n):
ADC Failure
S(n):
Memory Failure
S(n):
Broken Glass
S(n):
Reference
Failure
S(n):
PT Failure
S(n):
Calibrating
S(n):
Cal Failed
S(n):
PV Out of Limits
Cause
Failure of the analog to digital converter in the
sensor/sensor module.
Sensor configuration data is corrupt, or the
sensor's non-volatile memory is faulty.
The sensor configuration may be affected, and
changes may not be maintained after power
cycle.
Impedance measurement across glass tip of
sensor has changed significantly, suggesting a
broken glass electrode.
The measurement taken from the reference
electrode is invalid indicating that the
reference electrode in the sensor has failed.
The Reference Failure diagnostic indicates
that the sensor has reached the end of its
serviceable life and must be replaced.
The measurement taken from the temperature
sensor is invalid indicating that the
temperature sensor has failed, or the
associated connections are either open-circuit
or short-circuit.
Sensor calibration is in progress.
The most recent sensor calibration has failed,
calibration coefficients have not been updated
and the previous values continue to be
applied.
Process value (PV) measured is outside the
specified limits of the sensor.
Refer to the sensor data sheet to determine
the operating range.
Recovery action
Cycle power to the transmitter.
If Sensor ADC Failure persists, contact local service organization.
Cycle power to the transmitter.
If Sensor Memory Failure persists, check all configuration parameters
for all sensors and correct any errors. Save the configuration to SD card
or via Bluetooth App.
Reset the sensor to defaults from the Sensor Setup menu and reload the
saved configuration.
If Sensor Memory Failure persists, contact local service organization.
Check the sensor electrode visually for signs of damage.
If the sensor appears intact, power cycle the instrument and allow 5
minutes for the signal to settle.
If the Broken Glass persists then contact local service organization.
Check the sensor electrode visually for signs of damage.
If the sensor appears intact, power cycle the instrument and allow 5
minutes for the signal to settle.
If the Reference Failure persists then the sensor must be replaced,
contact local service organization.
Visually inspect the sensor/temperature sensor for signs of damage. A
damaged sensor must be replaced.
EZLink digital sensors: Cycle power to the transmitter.
Analog sensors: Check wiring to sensor module terminals 5 to 8.
If Process Temperature Failure persists, contact local service
organization
Diagnostic clears once calibration is complete
Visually inspect sensor tip for signs of damage or dirt and clean if
necessary.
Check that sensor tip is fully submerged in the solution.
Ensure that the correct buffer solutions have been selected in the
transmitter.
Ensure that the buffer solutions have been correctly made up.
Repeat calibration, if Calibration Failed persists, this may indicate that
the sensor has reached the end of its serviceable life and must be
replaced.
Check the process and the position of the sensor.
If PV Out of Limits is consistently active it may be necessary to replace
the sensor with an alternative with a wider, or more appropriate
operating range. Contact local service organization for potential
solutions
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