Emerson OXYMITTER 4000 - Manual (Page 121)

Instruction Manual
IB-106-340 Rev. 3.0
December 2003
Rosemount Analytical Inc. A Division of Emerson Process Management Troubleshooting 8-17
Oxymitter 4000
DIAGNOSTIC
ALARMS
TEST
POINTS
HEATER T/C
HEATER
O2 CELL
CALIBRATION
CALIBRATION RECOMMENDED
O2 CELL mV +
O2 CELL mv -
HEATER T/C +
HEATER T/C -
INC INC
DEC DEC
HIGH
GAS
LOW
GAS
CAL
TEST GAS +
PROCESS -
% O2
SW2
TP1
J1
TP2
TP3
RED YEL GRN ORG
TP4
TP5
TP6
ON
37260031
Alarms
O2 Cell Bad
LOI
KEYPAD
Figure 8-15. Fault 13, Invalid Slope
m. Fault 13, Invalid Slope
Figure 8-15 shows the electronic assembly
for an Oxymitter 4000 with a membrane
keypad (upper view) and an Oxymitter 4000
with an LOI (lower view).
Membrane Keypad. When Fault 13 is de-
tected, the CALIBRATION LED flashes
once, pauses for three seconds, and re-
peats.
1. During a calibration, the electronics
calculates a slope value. If the value of
the slope is less than 35 mV/deg or
more than 52 mV/deg, 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 at-
tach a multimeter to TP1+ and TP2-,
sample gas measurements are:
8% O
2
≈ 23 mV
0.4% O
2
≈ 85 mV
3. Power down the Oxymitter 4000 and
remove it from the stack.
4. Replace the cell per paragraph 9-4i,
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.