Rosemount 6888Xi, Reference Manual, Page: 71 / 114

Configuration, Startup and Operation 63
Reference Manual Section 3: Configuration, Startup and Operation
00809-0100-4892 January 2019
8. Use the stylus on the screen to select SEND to update the 6888Xi.
9. From the SENSOR menu, select HIGH TEMP ALM SP.
10. Use the stylus on the screen keypad to tenter the high temperature alarm set point value.
The value must be 750 °C and 850 °C. Press ENTER when finished.
11. Use the stylus on the screen to select SEND to update the 6888Xi
12. From the SENSOR menu, select HEATER LATCH OFF.
13. Press the RIGHT arrow key to edit the value. Use the UP and DOWN arrow keys to select the
mode.
No – Heater turns off above set point, then turns back on if process falls below set point
Yes – Heater turns off above set point, but does not then turn back on if process falls
below set point
14. Use the stylus on the screen keypad to press ENTER when finished.
15. Use the stylus on the screen to select SEND to update the 6888Xi.
3.8 Calibration
3.8.1 General
New O
2
cells may operate for more than a year without requiring calibration, but older cells may
require recalibration every few weeks as they near the end of their life.
A CALIBRATION RECOMMENDED alarm provides notice of when a calibration is required. This
strategy ensures that the O
2
reading is always accurate and eliminates many unnecessary cali-
brations based on calendar days or weeks since previous calibration.
The O
2
Probe(s) can be calibrated manually through the handheld 375/475 Field Communicator
or the 6888Xi. Fully automatic calibration can be performed automatically using the 6888Xi and
the SPS 4001B Single Probe Autocalibration Sequencer or the IMPS 4000 Intelligent Multiprobe
Sequencer.
FIGURE 3-7. Calibration Methods, Simplified