Figure 8-15. Fault 13, Invalid Slope - Emerson Rosemount Analytical Oxymitter 4000 Instruction Manual

Hazardous Area Oxymitter 4000
DIAGNOSTIC
ALARMS
CALIBRATION RECOMMENDED
TEST
POINTS
INC INC
HIGH LOW
GAS GAS
DEC DEC
KEYPAD
Alarms
O2 Cell Bad
LOI

Figure 8-15. Fault 13, Invalid Slope

Rosemount Analytical Inc. A Division of Emerson Process Management
HEATER T/C
HEATER SW2
O2 CELL
CALIBRATION
J1
O2 CELL mV +
TP1
O2 CELL mv -
TP2
HEATER T/C +
TP3
HEATER T/C -
TP4
CAL
TEST GAS +
TP5
PROCESS -
TP6
% O2
37260031
Instruction Manual
m. Fault 13, Invalid Slope
Figure 8-15 shows the electronic assembly
for a Hazardous Area Oxymitter 4000 with
a membrane keypad (upper view) and a
Hazardous Area Oxymitter 4000 with an
LOI (lower view).
Membrane Keypad. When Fault 13 is
detected, the CALIBRATION LED flashes
once, pauses for three seconds, and
repeats.
1. During a calibration, the electronics
calculates a slope value. If the value
of the slope is less than 35 mV/dec or
more than 52 mV/dec, the slope alarm
will be active until the end of the purge
cycle.
2. See paragraph 9-2, Calibration. Verify
the calibration by carefully repeating it.
Ensure the calibration gases match
the calibration gas parameters. If you
attach a multimeter to TP1+ and TP2-,
sample gas measurements are:
8% O ≈ 23 mV
2
≈ 85 mV
0.4% O
2
3. Power down the Hazardous Area
Oxymitter 4000 and remove it from
the stack.
4. Replace the cell per paragraph 9-4h,
Cell Replacement.
LOI. When Fault 13 is detected, the LOI
displays the "O2 Cell Bad" message. Refer
to the comments and procedures in para-
graphs 1 through 4 above.
IB-106-340C Rev. 4.1
July 2004
Troubleshooting 8-17
8