Emerson 3081FG instruction manual Cell Impedance, Previous Slope Previous Constant

Instruction Manual

IB-106-3081 Rev. 1.5 September 2002

Model 3081FG

O2 CONCENTRATION O2 CONCENTRATION

%

%

O2 CELL

IMPEDANCE STATUS

26020020

Figure 3-23. CELL IMPEDANCE

d.CELL IMPEDANCE

Refer to Figure 3-23. Use this screen to ex- amine the O2 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.

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 O2 on the reference and pro- cess sides of the cell. Press NEXT to ac- cess the MAX CELL T 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 O2 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.

O2 CONCENTRATION

%

CALCHECK CELL

CONSTANT VALUE

26020053

Figure 3-25. PREVIOUS CONSTANT

3-12 Startup and Operation Rosemount Analytical Inc. A Division of Emerson Process Management