Emerson Rosemount OCX 8800 Reference Manual page 112

Foundation Fieldbus
Table 7-3: Descriptions of PlantWeb Alerts
Alerts Alarms
Sensor Malfunc- Transducer block:
tion 1. O
2. Comb Cell Er-
ror
102
AMS tab
Sensor Alerts
Cell Open
2
What does the Recommended
alert indicate? action
This alert is active Check sensor
when the sensor wires for loose or
is indicating a very broken connec-
high or unexpec- tions or replace
ted output. the cell.
Description
1. The oxygen
cell interface
is designed to
indicate a very
high output if
the cell be-
comes discon-
nected from
the electron-
ics. It is possi-
ble that a wire
connection to
the cell, either
in the probe
tip or at the
electronics, is
loose or bro-
ken. The cell
may also be
damaged
from mechan-
ical stress. In
extreme ca-
ses, a very low
oxygen con-
centration in
the process
may cause
this alarm. Di-
agnosis must
be done at the
analyzer. Re-
fer to
Section 8.2 for
details.
2. This problem
could be
caused by a
mechanical
failure in the
sensor hous-
ing or at the
electronics.
An open cir-
cuit in the
combustible
sensor could
OCX 8800