Emerson Rosemount OCX 8800, Instruction Manual

Page: 77 / 306

Section 3: Configuration and
Startup
April 2017
Instruction Manual
IM-106-880C, OI
3.8 Calibration Tolerance Feature
The calibration tolerance feature provides a mechanism to fail a calibration if the calibration
measurement does not fall within a specific tolerance of the test gas value. The tolerance is
preset within the Hazardous Area OCX 8800 software and is not user adjustable. The tolerance
is different between the oxygen and combustibles test gases. For oxygen, the calibration will fail
if the measured value differs by more than ±10% of the configured value. For combustibles, the
calibration will fail if the measured value differs by more than ±30% of the configured value.
A Hazardous Area OCX 8800 shipped from the factory must be configured before the
calibration tolerance feature can be implemented. This same process must be performed any
time a replacement card stack is installed.
3.8.1 Configuring the Calibration Tolerance Feature with the Field
Communicator - HART
1. Use the 375 Field Communicator or AMS software to access the HART menu.
2. From the DETAILED SETUP menu, select CAL SETUP.
3. From the CAL SETUP menu, select O2 CAL PARAMS.
4. To enable the calibration tolerance feature for the oxygen calibration, from the O2 CAL
PARAMS, select O2 Tol Check. Select On to enable the calibration tolerance feature.
5. Back out to the CAL SETUP menu, select COe CAL PARAMS.
6. To enable the calibration tolerance feature for the combustibles calibration, from the COe
CAL PARAMS, select COe Tol Check. Select On to enable the calibration tolerance feature.
3.8.2 Configuring the Calibration Tolerance Feature with the Field
Communicator - Fieldbus
1. Use the 375 Field Communicator or AMS software to access the Fieldbus menu.
2. From the TRANSDUCER block menu, select O2 CAL/COe CAL.
3. From the O2 CAL/COe CAL menu, select O2 CAL SETUP/COe CAL SETUP.
4. From the O2 CAL SETUP/COe CAL SETUP menu, select O2 Tolerance Check/COe
Tolerance Check. Select Yes to enable the calibration tolerance feature.
3.8.3 Configuring the Calibration Tolerance Feature with the LOI
1. Use the "Z" pattern to enter the LOI menu tree.
2. From the SYSTEM menu, select Calib Setup.
3. From the Calib Setup menu, select the following:
• O2 Tol Check - Select Yes to enable the calibration tolerance feature for the
oxygen calibration.
• Comb Tol Check - Select Yes to enable the calibration tolerance feature for the
combustibles calibration.
52 Calibration Tolerance Feature