Emerson Rosemount Oxymitter 4000 Reference Manual page 72

Rosemount Oxymitter 4000
72
Test Points
Test points 1 through 6 allow you to monitor with a multimeter: the heater
thermocouple, the O cell millivolt value, and the process O
2
• TP1 and TP2 monitor the oxygen cell millivolt output, which equates to the
percentage of oxygen present.
• TP3 and TP4 monitor the heater thermocouple.
• TP5 and TP6 monitor the process gas or the calibration gas parameter.
Cal LED
The CAL LED is on steady or flashing during calibration. Further information is available in
Section 9: Maintenance and Service.
Keys
INC and DEC. The INC and DEC keys are used to set the values of the calibration gases.
Attach a multimeter across TP5 and TP6. The calibration and process gases can now be
monitored. Pressing the INC or DEC once will cause the output to switch from the
process gas to the calibration gas. Pressing INC or DEC a second time will increase or
decrease the calibration gas parameter. If the keys have been inactive for one minute, the
output reverts to the process gas. When a calibration has been initiated, the value at TP5
and TP6 is the % O seen by the cell.
2
Oxygen levels, as seen on the multimeter, are:
8.0% O = 8.0 volts DC
2
0.4% O = 0.4 volts DC
2
Cal
The CAL key can:
• Initiate a calibration.
• Sequence through calibration.
• Abort the calibration.
NOTE
Refer to Section 9: Maintenance and Service, for calibration instructions.
Keys
Refer to Remote Powered Loop LCD manual for calibration and operation.
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2
Startup and Operation with Membrane Keypad
July 2018