Emerson 6888Xi Carbon Monoxide Alarm User Manual


 
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Overview
The 6888Xi is specifically designed to control a zirconium oxide probe for measuring oxygen,
usually the O2 remaining from a combustion process. Call the Rosemount Analytical Customer
Support Center (CSC) in Solon, Ohio, to get recommendations for other oxygen probes. 800-
433-6076 (US and Canada), or 440-914-1261 (International).
The 6888Xi electronics has several main functions:
1. Heater Control - The electronics receives a type K thermocouple input from an O
2
probe and
switches power on and off to the probe's heater in order to maintain a temperature setpoint
of 736 degrees C.
2. Signal Conditioning - The electronics receives the raw millivolt signal from the O
2
sensing
cell, then linearizes and amplifies the signal to provide a linear 4-20 mA output signal used
for recording or as an input into a DCS system for control purposes.
3. Calibration - A bottled calibration gas of known value is typically flowed into the probe's sen-
sor to verify that it is reading correctly. If the signal is out of calibration, the calibration gas is
used to adjust the 4-20 mA output signal. During calibration the 6888Xi prompts the techni-
cian to flow two calibration gases into the probe and, with the calibration gases flowing,
automatically adjusts the O
2
signal. With the addition of a Single Probe Sequencer (SPS), the
6888Xi Advanced Electronics can also switch the calibration gases on and off.
4. Diagnostics - Multiple alarms are available for display. The alarm displays are intended to
assist a technician in locating where an instrument problem may reside.
The 6888Xi Advanced Electronics has been verified to operate the following probes:
• Westinghouse 218 and World Class
• Rosemount Analytical Oxymitter
• Yokogawa
Technical Support Hotline
For assistance with technical problems, please call the Customer Support Center (CSC).
Phone: 1-800-433-6076 1-440-914-1261
In addition to the CSC, you may also contact Field Watch. Field Watch coordinates Emerson
Process Management’s field service throughout the U.S. and abroad.
Phone: 1-800-654-RSMT (1-800-654-7768)
e-mail: GAS.CSC@emerson.com
web: www.raihome.com
2 Introduction
S
ection i: Introduction 6888Xi Advanced Electronics Instruction Manual
December 2012 PN 51-6888Xi
RISKOFELECTRICAL SHOCK
WARNING:REFER TOINSTRUCTIONMANUAL
PROTECTIVECONDUCT OR TERMINAL
EARTH(GROUND) TERMINAL
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