Emerson Rosemount 5081FG, Reference Manual

Page: 55 / 105

Reference Manual
00809-0100-4882, Rev AB
May 2019
Rosemount 5081FG
3-19
Cell Impedance
Refer to Figure 3-23. Use this screen to examine 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; however, failure will occur soon. Pressing
NEXT accesses the CURRENT SLOPE screen.
NOTE
Temperature influences cell impedance. Wait until the cell is at operating
temperature before checking cell impedance. If checked before the cell
reaches 550°C (1022°F), this screen displays a fail indication.
Current Slope
Refer to Figure 3-24. Use this screen to examine 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
degrading. Press NEXT to access the CURRENT CONSTANT screen.
Figure 3-23. Cell Impedance
Figure 3-24. Current Slope