Emerson 3081FG - Manual (Page 42)

Instruction Manual
IB-106-3081 Rev. 1.5
September 2002
3-12 Startup and Operation Rosemount Analytical Inc. A Division of Emerson Process Management
Model 3081FG
O CELL
IMPEDANCE STATUS
2
26020020
%
O CONCENTRATION
2
Figure 3-23. CELL IMPEDANCE
d. CELL IMPEDANCE
Refer to Figure 3-23. Use this screen to ex-
amine the O
2
cell impedance status. GOOD
indicates the cell is operating normally.
WARN indicates the cell has degraded but
is still operational. HI indicates that the cell
has degraded but is still operational; how-
ever, failure will occur soon. Pressing NEXT
accesses the PREVIOUS SLOPE screen.
NOTE
Temperature influences cell imped-
ance. Wait until the cell is at operating
temperature before checking cell im-
pedance. If checked before the cell
reaches operating temperature [550°C
(1022°F)], this screen displays a fail
indication.
e. PREVIOUS SLOPE
Refer to Figure 3-24. Use this screen to ex-
amine the slope calculated from the most
recent calibration check. The slope is the
amount of cell voltage generated for a given
O
2
value. For each calibration check, record
the slope over the life of the probe. Tracking
the slope will indicate if the probe is de-
grading. Press NEXT to access the PREVI-
OUS CONSTANT screen.
%
O CONCENTRATION
2
CALCHECK CELL
SLOPE VALUE
26020052
Figure 3-24. PREVIOUS SLOPE
f. PREVIOUS CONSTANT
Refer to Figure 3-25. Use this screen to ex-
amine the cell zero constant calculated from
the most recent calibration check. The con-
stant represents the voltage generated by
the cell when no difference exists between
the amount of O
2
on the reference and pro-
cess sides of the cell. Press NEXT to ac-
cess the MAX CELL T screen.
%
O CONCENTRATION
2
CALCHECK CELL
CONSTANT VALUE
26020053
Figure 3-25. PREVIOUS CONSTANT