AW T4 20 |
U N I V ER S A L 4 - W I R E , D UA L- I N P U T T R A N SM I T T ER | O I/AW T4 2 0 - EN R E V. B
91
NAMUR
icon
Diagnostic
message
Cause
Recovery action
S(n):
PV Out of Limits
Process value (PV) measured is outside the
specified limits of the sensor.
Refer to the sensor data sheet to determine
the operating range.
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.
S(n):
Internal Temp Out
of Range
Internal temperature of the turbidity sensor is
outside its recommended operating range.
This may cause the measurements to be
inaccurate.
Reposition the sensor to avoid extreme temperatures.
Ensure that the ambient temperature of the sensor is within its
operating range. 0 to 60 °C [32 to 140 °F].
If
Internal Temperature Out of Range
persists, contact local service
organization.
S(n):
Excess Light
The turbidity sensor determines turbidity using
Nephelometric detection, by measuring the
amount of light scattered by the sample at 90°
from the direction of illumination.
Excessive ambient light can interfere with this
and result in inaccurate readings.
Shade the sensor, or if possible move the sensor to a location where
it is not affected by ambient light.
S(n):
Service Due
The turbidity sensor requires servicing.
The sensor performance degrades over time
and servicing is required to maintain accuracy.
Contact local service organization.
S(n):
Replace Wiper
The wiper blade on the turbidity sensor is
reaching the end of its expected useful life.
Measurement quality may be affected due to
inadequate cleaning.
Replace wiper and Reset Sensor Lifetime in
Sensor Setup
.
S(n):
Replace Wiper
The wiper blade on the turbidity sensor has
reached the end of its expected useful life.
Measurement quality may be affected due to
inadequate cleaning.
Replace wiper and
Reset Sensor Lifetime
in
Sensor Setup.
S(n):
Service Overdue
The turbidity sensor requires servicing.
The sensor performance degrades over time
and servicing is required to maintain accuracy.
Contact local service organization.
S(n):
LED Expired
This LED in the sensor has reached the end of
its expected lifespan, and so is likely to fail.
Contact local service organization.
