Emerson Rosemount 6888A Reference Manual
Rosemount™ 6888A
O2 Combustion Flue Gas Transmitter
Reference Manual
00809-0100-4890, Rev AA
July 2018
Essential instructions
Read this page before proceeding!
EmersonTM designs, manufactures, and tests its products to meet many national and international standards. Because these
instruments are sophisticated technical products, you must properly install, use, and maintain them to ensure they continue to
operate within their normal specifications. The following instructions must be adhered to and integrated into your safety program
when installing, using, and maintaining Emerson products. Failure to follow the proper instructions may cause any one of the
following situations to occur: loss of life, personal injury, property damage, damage to this instrument, and warranty invalidation.
• Read all instructions prior to installing, operating, and servicing the product.
• If you do not understand any of the instructions, contact your Emerson representative for clarification.
• Follow all warnings, cautions, and instructions marked on and supplied with the product.
• Inform and educate your personnel in the proper installation, operation, and maintenance of the product.
• Install equipment as specified in the installation instructions of the appropriate instruction manual and per applicable local
and national codes. Connect all products to the proper electrical and pressure sources.
• To ensure proper performance, use qualified personnel to install, operate, update, program, and maintain the product.
• When replacement parts are required, ensure that qualified people use replacement parts specified by Emerson.
Unauthorized parts and procedures can affect the product's performance, place the safe operation of your process at risk,
and VOID YOUR WARRANTY. Look-alike substitutions may result in fire, electrical hazards, or improper operation.
• Ensure that all equipment doors are closed and protective covers are in place, except when maintenance is being performed
by qualified people, to prevent electrical shock and personal injury.
NOTICE
The information contained in this document is subject to change without notice.
NOTICE
The Field Communicator must be upgraded to System Software 2.0 with graphic license for operation with the RosemountTM 6888A
O2 Transmitter. The AMS software must be upgraded to AMS 8.0 or above. Contact Emerson's Global Service Center (GSC) at
+1-800-833-8314 to upgrade the Field Communicator software to System Software 2.0 with graphic license.
Preface
The purpose of this manual is to provide information concerning components, functions, installation, and maintenance of the
Rosemount 6888A O2 Transmitter.
Some sections may describe equipment not used in your configuration. You should become thoroughly familiar with the operation
of this module before operating it. Read this reference manual completely.
Symbols
Earth (ground) terminal
Protective conductor terminal
Risk of electrical shock
Refer to reference manual.
The following definitions apply to Warnings, Cautions, and Notices found throughout this publication.
WARNING!
Highlights an operation or maintenance procedure, practice, condition, statement, etc., which if not strictly observed, could result in
injury, death, or long-term health hazards of personnel.
CAUTION!
Highlights an operation or maintenance procedure, practice, condition, statement, etc., which if not strictly observed, could result in
damage to or destruction of equipment or loss of effectiveness.
NOTICE
Highlights an essential operating procedure, condition, or statement.
Overview
The 6888A is Rosemount's latest in-situ probe offering intended for combustion flue gas service. Similar to our previous World Class
and Oxymitter probes, there is no sampling system. The sensing cell is mounted to the end of a probe (18 in., 3 ft, 6 ft, 9 ft, or 12 ft
long) that is directly inserted into the flue gas stream.
The sensing cell is of similar design to the World Class and Oxymitter cells, using the zirconium oxide sensing principle. The cell is
heated and maintained at 736 °C (1357 °F) setpoint and generates a logarithmic MV signal proportional to the partial pressure
difference of oxygen between the reference side of the cell (usually instrument air at 20.95% O2) and the process side of the cell
(usually combustion flue gases). For more information on sensing cell operation, see Chapter 4.
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's field service throughout the US and
abroad.
Phone: 1-800-654-RSMT (1-800-654-7768)
Email: Gas.CSC@emerson.com
Web: www.Emerson.com/RosemountGasAnalysis
Contents
Contents
Chapter 1 Description and specifications ........................................................................................1
1.1 Component checklist ...................................................................................................................1
1.2 Technical support hotline ............................................................................................................ 2
1.3 System overview ..........................................................................................................................3
1.4 System configurations ................................................................................................................. 3
1.4.1 Transmitter probe, only .................................................................................................3
1.4.2 Standard housing transmitter probe plus Rosemount 6888Xi Electronics ......................3
1.4.3 Transmitter probe and Rosemount 6888Xi with flame safety interlock ......................... 4
1.4.4 Transmitter probe with integral autocal, Rosemount 6888Xi, and HART
communications ........................................................................................................... 4
1.4.5 Transmitter probe with integral autocal and FOUNDATION™ Fieldbus (FF)
communications ........................................................................................................... 4
1.4.6 Direct replacement (DR) probe with traditional architecture Rosemount 6888Xi
electronics .................................................................................................................... 5
1.4.7 Wireless capability ........................................................................................................ 5
1.4.8 Automatic calibration ....................................................................................................5
1.4.9 Communication options ............................................................................................... 6
1.5 Probe options .............................................................................................................................. 8
1.5.1 Diffusion elements ........................................................................................................8
1.6 Rosemount 6888A product matrix .............................................................................................10
1.7 Rosemount 6888Xi product matrix ............................................................................................12
1.8 Transmitter/DR probe specifications ..........................................................................................14
®
Chapter 2 Install ...........................................................................................................................17
2.1 System considerations ...............................................................................................................18
2.2 Mechanical installation .............................................................................................................. 19
2.2.1 Install probe ................................................................................................................ 20
2.2.2 Variable insertion ........................................................................................................ 24
2.3 Electrical installation ..................................................................................................................26
2.3.1 Wiring for Rosemount 6888 Transmitter probe only (no Rosemount 6888Xi
Electronics) ................................................................................................................. 26
2.3.2 Standard housing transmitter probe plus Rosemount 6888Xi Electronics ....................28
2.3.3 Transmitter probe with single-channel Xi and flame safety interlock ...........................32
2.3.4 Transmitter probe with integral autocal and HART communications ...........................35
2.3.5 Wire the Rosemount 6888A Transmitter probe with integral autocal and FOUNDATION
Fieldbus communications ........................................................................................... 37
2.3.6 Wire the traditional architecture system with direct replacement probe (no electronics
inside) ......................................................................................................................... 38
2.3.7 Wire the traditional architecture cable connections .................................................... 40
2.4 Pneumatic installation ............................................................................................................... 42
2.4.1 Reference air package ................................................................................................. 42
2.4.2 Calibration gas ............................................................................................................ 45
Chapter 3 Configuration, startup, and operation .......................................................................... 47
3.1 Power up Rosemount 6888 Transmitter without Rosemount 6888Xi .........................................47
3.2 Power up the Rosemount 6888 Transmitter with single/dual channel or single channel and flame
safety interlock Rosemount 6888Xi ........................................................................................... 48
™
Reference Manual i
Contents
3.3 Power up the Rosemount 6888 direct replacement probe (no electronics inside) with traditional
architecture Rosemount 6888Xi ................................................................................................ 48
3.4 Rosemount 6888Xi Quick Start Wizard ...................................................................................... 49
3.5 Re-initiating Rosemount 6888Xi wizard ..................................................................................... 50
3.6 Calibration .................................................................................................................................50
3.6.1 Manual/semi-automatic calibration ............................................................................ 50
3.6.2 Fully automatic calibration ..........................................................................................51
3.6.3 Other features associated with calibration .................................................................. 52
3.7 Startup ...................................................................................................................................... 75
3.7.1 Error conditions ...........................................................................................................75
3.8 System parameter descriptions ................................................................................................. 76
3.9 Parameter setup ........................................................................................................................ 79
3.9.1 Test gas values ............................................................................................................ 79
3.9.2 Set test gas times ........................................................................................................79
3.9.3 Track output during calibration ...................................................................................80
3.9.4 Configure analog output .............................................................................................81
3.10 Calibrate ....................................................................................................................................81
3.10.1 Calibration procedure ................................................................................................. 82
3.10.2 Calibration log .............................................................................................................83
3.10.3 Reset calibration ......................................................................................................... 83
3.11 D/A trim .....................................................................................................................................84
Chapter 4 Troubleshooting .......................................................................................................... 87
4.1 Overview ................................................................................................................................... 87
4.2 General ......................................................................................................................................89
4.2.1 Grounding ...................................................................................................................89
4.2.2 Electrical noise ............................................................................................................ 89
4.2.3 Electrostatic discharge ................................................................................................89
4.3 Alarm indications .......................................................................................................................90
4.4 Identifying and correcting fault indications ................................................................................91
4.5 Calibration passes, but still reads incorrectly ..............................................................................92
4.5.1 Probe passes calibration, O2 still reads high .................................................................93
4.5.2 Probe passes calibration, O2 still reads low .................................................................. 94
4.5.3 How do I detect a plugged diffuser? ............................................................................ 94
4.5.4 Can I calibrate a badly plugged diffuser? ......................................................................94
Chapter 5 Maintenance and service ..............................................................................................97
5.1 Overview ................................................................................................................................... 97
5.2 Maintenance intervals ................................................................................................................97
5.3 Calibrate ....................................................................................................................................98
5.3.1 Manual calibration ...................................................................................................... 98
5.3.2 Automatic calibration ................................................................................................. 98
5.4 Repair ........................................................................................................................................ 98
5.4.1 Remove and replace probe ..........................................................................................99
5.4.2 Replace transmitter board ...........................................................................................99
5.4.3 Replace DR terminal board ........................................................................................102
5.4.4 Heater strut replacement ..........................................................................................103
5.4.5 Cell replacement .......................................................................................................105
5.4.6 Diffusion element replacement .................................................................................108
5.4.7 Blind cover replacement ............................................................................................110
Chapter 6 Replacement parts ..................................................................................................... 113
Chapter 7 Optional accessories ...................................................................................................115
ii Rosemount 6888A
Contents
7.1 Asset Management Solutions (AMS) ........................................................................................ 115
7.2 By-Pass Packages ..................................................................................................................... 115
7.3 Rosemount SPS 4001B Single Probe Autocalibration Sequencer ..............................................116
7.4 Rosemount IMPS 4000 Intelligent Multiprobe Test Gas Sequencer .......................................... 117
7.5 O2 calibration gas .................................................................................................................... 118
7.6 Optional Rosemount OxyBalance Display and Averaging System .............................................119
Appendices and reference
Appendix A Rosemount™ 6888 product certifications ....................................................................121
A.1 European Directive information ...............................................................................................121
A.2 Ordinary location certification ................................................................................................. 121
A.3 Installing equipment in North America .................................................................................... 121
A.4 Rosemount™ 6888A In-Situ Oxygen Transmitter for General Purpose Locations .......................121
A.4.1 USA ...........................................................................................................................121
A.4.2 Canada ......................................................................................................................122
A.4.3 Europe ...................................................................................................................... 122
A.5 Rosemount™ 6888Xi Digital Transmitter for General Purpose Locations .................................. 122
A.5.1 USA ...........................................................................................................................122
A.5.2 Canada ......................................................................................................................122
A.6 Rosemount™ SPS4001B and IMPS4000 Autocalibration Devices for General Purpose
Locations ................................................................................................................................. 123
A.6.1 USA/Canada ..............................................................................................................123
Appendix B Safety data ................................................................................................................. 125
B.1 Safety instructions for the wiring and installation of this apparatus ..........................................125
Reference Manual iii
Contents
iv Rosemount 6888A
Description and specifications
1 Description and specifications
1.1 Component checklist
A typical Rosemount™ 6888A O2 Combustion Flue Gas Transmitter should contain the
items shown in Figure 1-1. A complete Oxygen Analyzer system includes some or all of the
equipment shown. However, this manual describes the Rosemount 6888A Transmitter
only.
Also, use the product matrix (Section 1.6) at the end of this section to compare your order
number against your unit. The first part of the matrix defines the model. The last part
defines the various options and features of the Rosemount 6888A. Ensure the features and
options specified by your order number are on or included with the unit.
Reference Manual 1
Description and specifications
Typical System PackageFigure 1-1:
A. Quick start guide
B. Optional mounting or adapter plate
C. Optional traditional architecture cable
D. Optional reference and calibration gas accessories
E. 6888A integral autocal housing
F. 6888A probe with standard terminations/electronics housing
G. Optional 6888Xi Advanced Electronics
1.2
2 Rosemount 6888A
Technical support hotline
For assistance with technical problems, please call the Customer Support Center (CSC).
• 1-RAI-AND-U (1-855-724 2638)
• 1-440-914-1261
In addition to the CSC, you may also contact Field Watch. Field Watch coordinates
Emerson's field service throughout the US and abroad.
• 1-800-654-RSMT (1-800-654-7768)
Emerson may also be reached via the Internet through email and the World Wide Web.
• Email: Gas.CSC@Emerson.com
• World Wide Web: www.Emerson.com/RosemountGasAnalysis
1.3 System overview
The 6888 is Rosemount's latest combustion flue gas oxygen analyzer. This product is
intended for measuring the flue gases resulting from any combustion process. It uses the
same heated sensing technology as the O2 sensors found in most automobiles. Contact
Rosemount's technical support group at 800-433-6076 for any applications other than
measuring combustion flue (exhaust) gases.
This product uses an in-situ sensor, i.e., the sensor is placed at the end of a probe, and the
probe extends directly into the flue gas duct or stack at a given length. The sensor is like a
thermocouple, generating its own millivolt signal based on the differences between a
reference gas (ambient or instrument air - always 20.95% O2) and the flue gases being
measured. There are several different arrangements of probes, electronics, and features
that are explained below and in the wiring diagrams.
Description and specifications
An optional Rosemount 6888Xi with HART® communication provides a convenient
operator interface for setup, calibration, and diagnostics. HART communication is still
present when using the Rosemount 6888Xi.
1.4
System configurations
1.4.1 Transmitter probe, only
The Rosemount 6888 probe has the electronics in the blue housing that controls the
heater temperature and also amplifies the raw O2 millivolt signal to a linear 4-20 mA. The
4-20 mA signal lines can be run directly to the control room and also power the transmitter
electronics. As with most other Rosemount transmitters, measuring pressure,
temperature, and flow setup is conducted through HART communications via a 475
handheld communicator or via Asset Management Solutions (AMS).
1.4.2
Standard housing transmitter probe plus Rosemount
6888Xi Electronics
The Rosemount 6888Xi Electronics serve as a local operator interface unit with a back-lit
display and keypad. It is capable of two channels, serving two Rosemount 6888 probes.
The Rosemount 6888Xi also carries these optional advanced features:
• Fully automatic calibration. Requires Xi O2 Cal Autocalibration system
Reference Manual 3
Description and specifications
• Loss of flame contact for powering down the heater in the event of a flame-out
• Heaterless operation at process temperatures above 550 °C (1022 °F). This feature
• Plugged diffuser diagnostic operates by measuring the return-to-process rate after
• Stochiometer - If a furnace goes into a reducing condition (zero % O2), this feature
• Programmable reference - Permits more accurate readings at near-ambient O
• A cal check capability. New calibration values are not automatically stored after a
• Tolerance check that will alarm if the wrong test gases are being used or if a bottle
condition in a furnace.
will also permit operation above the heater setpoint of 736 °C (1357 °F). Sensing cell
life will be shortened by operation above 800 °C (1472 °F), however.
calibration gas has been stopped. This feature also includes auto gas switching when
the reading settles out versus waiting for configured gas flow time to expire.
will determine how far.
2
levels (20.95% O2).
calibration. An accept/reject calibration feature can be enabled or disabled so that
the techniciean or operator can decice to accept or reject a potentially large change
in calibration values.
runs out in the middle of a calibration. Take care to ensure gas 1 and gas 2
calibration gases are properly configured if the tolerance check feature is enabled.
1.4.3 Transmitter probe and Rosemount 6888Xi with flame
safety interlock
A flame safety interlock by Emerson is available for heater power disconnect whenever
there is a loss of the process flame or a heater runaway condition (heater overtemperature) in the O2 probe. This input is internally powered by the Rosemount 6888Xi
and is actuated via a dry contact output from your flame scanner. A closed contact
indicates a flame is present. An open contact indicates a loss of flame. This feature is also
available with the integral autocal housing.
1.4.4
Transmitter probe with integral autocal, Rosemount
6888Xi, and HART® communications
This probe contains gas-switching solenoids so that the Rosemount 6888Xi electronics can
control the introduction of calibration gases. Calibrations can be initiated via a calibration
recommended diagnostic, time since last calibration, manually via external dry contact,
HART communications, or from the Rosemount 6888Xi local operator interface keypad.
The integral autocal feature can only be implemented when the probe is used with a
Rosemount 6888Xi.
1.4.5
Transmitter probe with integral autocal and
FOUNDATION™ Fieldbus (FF) communications
This probe contains gas-switching solenoids that can control the introduction of
calibration gases for calibration. Calibrations can be initiated automatically via a calibration
recommended diagnostic, time since last calibration, manually via the optional
4 Rosemount 6888A
Description and specifications
Rosemount 6888Xi keypad, FF communications via the 475 communicator, or AMS
console. Unlike the HART transmitter electronics, the FF version can execute automatic
calibrations either with or without the optional Rosemount 6888Xi electronics. Likewise,
advanced features can be implemented either with or without the optional Rosemount
6888Xi.
1.4.6 Direct replacement (DR) probe with traditional
architecture Rosemount 6888Xi electronics
Here there are no electronics inside the probe head, so the raw sensor signals for the
heater thermocouple and zironium oxide O2 sensor are sent to a remote Rosemount
6888Xi Electronics. The Rosemount 6888 traditional architecture electronics will also
directly apply power to the probe heater in order to maintain the correct sensor
temperature. This arrangement calls for a 7-conductor cable to carry this power and the
sensor signals. Maximum length for the cable is 200 feet. This probe will also operate on
previous Westinghouse/Rosemount electronics (World Class and Oxymitter), as well as
many competitive electronics.
1.4.7 Wireless capability
1.4.8
Both the transmitter electronics in the head of the probe and the Rosemount 6888Xi
Electronics communicate over HART communications and can implement wireless
communications via Emerson Wireless 775 THUM™ Adapter.
Automatic calibration
Calibrations consist of introducting bottled gases of known value into the probe so that
the electronics can make automatic adjustments to the O2 readings to match the bottled
gas value.
Emerson recommends 0.4% O2 and 8% O2 (balance nitrogen) gases. Never use nitrogen or
instrument air as calibration gases. Flowmeters (for calibration gases) and regulators and
flowmeters (for reference air) are available as loose components, mounted into an
optional manual calibration switching panel or a fully automatic calibration system
(Figure 1-2) where calibration solenoids are switched from the Rosemount 6888Xi
Advanced Electronics. See the Rosemount SPS 4001B Single Probe Autocalibration Sequencer
or Rosemount IMPS 4000 Intelligent Multiprobe Test Gas Sequencer manuals for additional
details.
Reference Manual 5
Description and specifications
Figure 1-2:
A. Manual calibration switching panel
B. Reference air set
C. Rosemount SPS 4001B or Rosemount IMPS 4000
D. Rosemount 6888Xi Advanced Electronics
E. Rosemount 6888A O2 Transmitter
Rosemount 6888A with Rosemount 6888Xi Advanced Electronics and
Autocalibration Sequencer
1.4.9
Communication options
A customer-supplied 375/475 Field Communicator and/or the optional Rosemount 6888Xi
Advanced Electronics accomplish Rosemount 6888A communications. Graphic displays
are available via the optional Rosemount OxyBalance Display and Averaging System.
Data communications
You can configure and diagnostically troubleshoot the Rosemount 6888A in one of two
ways:
1. Using the optional Rosemount 6888Xi Advanced Electronics allows local
communication with the electronics. The Rosemount 6888Xi also offers the
following optional advanced features:
• Fully automatic calibration.
• Optional flame safety interface (single probe version only).
• High temperature operation [above 700 °C (1292 °F) standard temperature].
• Stoichiometer feature provides the ability to indicate O2 efficiency when the
combustion process goes into reducing conditions (0% O2).
• Programmable reference provides enhanced accuracy when measuring at or
near O2 level (20.95% O2).
6 Rosemount 6888A
Description and specifications
• Plugged diffuser diagnostic to detect fouled diffuser.
2. Using the HART interface, the Rosemount's 6888A's 4-20 mA output line transmits
an analog signal proportional to the oxygen level. The HART output is superimposed
on the 4-20 mA output line. This information can be accessed through the following:
• Rosemount 375/475 Field Communicator: The handheld communicator requires
device description (DD) software specific to the Rosemount 6888A. The DD
software is supplied with many 375/475 units, but can also be programmed into
existing units at most Emerson service offices. See Chapter 3 for additional
information.
• Personal computer (PC): The use of a personal communicator requires AMS
software available from Emerson.
• Delta V and Ovation Distributed Control System (DCS) with AMS-inside
capability.
3. The Rosemount 6888A can also transmit HART information wirelessly via a wireless
THUM Adapter. The THUM Adapter threads into the Rosemount 6888A conduit port
and converts the 4-20 mA signal to a wireless protocol. All other HART information is
also transmitted.
In addition to the wireless THUM Adapter, a hard wire connection of the 4-20 mA
signal to the DCS may be used at the same time. More detailed information
regarding the application of the THUM Adapter is available in Product Data Sheet
00813-0100-4075.
Note
The 375 field communicator must be upgraded to System Software 2.0 with Graphic License for
operation with the Rosemount 6888A O2 transmitter. The AMS software must be upgraded to AMS
8.0 or above.
Contact Emerson's Global Service Center (GSC) at 1-800-833-8314 to upgrade the 375 field
communicator software to System Software 2.0 with Graphic License.
Optional Rosemount OxyBalance Display and Averaging
System
The optional Rosemount OxyBalance Display and Averaging System receives up to eight
4-20 mA signals from individual probes, trends individual outputs, and calculates four
programmable averages as additional 4-20 mA outputs. For more information, call
Rosemount at 1-800-433-6076.
Reference Manual 7
Description and specifications
Rosemount OxyBalance SystemFigure 1-3:
1.5 Probe options
1.5.1 Diffusion elements
The Rosemount 6888A is available with one of three diffusion elements fitted to the
process end. The basic diffusers provide for a constant outer probe tube diameter the full
length of the probe. When the Rosemount 6888A is used with an abrasive shield, the
diffuser body has a larger diameter with grooves to accept packing material to seal out fly
ash. The snubber and ceramic diffusers may also be fitted with a flash arrestor to reduce
the possibility of the probe igniting from flammable gases within the process.
WARNING!
FLAME AND EXPLOSION
The diffusers fitted with flash arrestors have been tested to provide a measure of protection in
preventing ignition of flammable gases. They are not intended to provide flame proof or
explosion proof protection for the Rosemount 6888A.
8 Rosemount 6888A
Description and specifications
Snubber diffusion assembly
The standard snubber diffusion assembly (Figure 1-4) is satisfactory for most applications;
however, the snubber diffuser should not be used in flue gas temperatures above 400 °C
(752 °F).
Snubber Diffusion AssemblyFigure 1-4:
Ceramic diffusion assembly
The ceramic diffusion assembly (Figure 1-5) is the traditional design for the probe. Used for
over 25 years, the ceramic diffusion assembly provides a greater filter surface area.
Ceramic Diffusion AssemblyFigure 1-5:
Cup-type diffusion assembly
The cup-type diffusion assembly (Figure 1-6) is typically used in high temperature
applications where frequent diffusion element plugging is a problem. The cup-type
difusion assembly is available with a 40 micron, sintered, Hastelloy element.
Reference Manual 9
Description and specifications
Hastelloy Cup-Type Diffusion AssemblyFigure 1-6:
1.6 Rosemount 6888A product matrix
Calibration GlassTable 1-1:
Part number Description
1A9919G01 Two disposable calibration gas bottles - 0.4%
and 8% O2, balance nitrogen - 550 liters each.
1A9919G02 Two flow regulators for calibration gas bottles
1A9919G03 Bottle rack
(1) Calibration gas bottles cannot be shipped via air freight.
Compare the configuration matrix below to the model number on the probe tag to
confirm the features present in this specific probe
Rosemount 6888A Product MatrixTable 1-2:
Model Description
6888A O2 Transmitter
Measurement
1OXY Oxygen, standard sensing cell
2OXY Oxygen, acid resistant stochiometric sensing cell
Probe length
1 18 in. probe, standard probe tube
2 18 in. probe, standard probe tube with abrasive shield
3 18 in. probe, abrasion resistant probe tube
4 3 ft probe, standard probe tube
5 3 ft probe, standard probe tube with abrasive shield
6 3 ft probe, abrasion resistant probe tube
(1)
(1)
10 Rosemount 6888A
Description and specifications
Rosemount 6888A Product Matrix (continued)Table 1-2:
7 6 ft probe, standard probe tube
8 6 ft probe, standard probe tube with abrasive shield
9 6 ft probe, abrasion resistant probe tube
A 9 ft probe, abrasion resistant probe tube
AA 9 ft probe, abrasion resistant probe tube with abrasive shield
B 12 ft probe, abrasion resistant probe tube
BA 12 ft probe, abrasion resistant probe tube with abrasive shield
Diffuser
1 Snubber 400 °C (752 °F)
1A Snubber with dust shield 400 °C (752 °F) (used with abrasive shield)
1F Snubber with flashback arrestor 400 °C (752 °F)
2 Ceramic 825 °C (1517 °F)
2A Ceramic with dust shield 825 °C (1517 °F) (used with abrasive shield)
2F Ceramic (825 °C) with flashback arrestor 825 °C (1517 °F)
3 Hastelloy 40 µm 705 °C (1292 °F)
3A Hastelloy with dust seal 40 µm 705 °C (1292 °F) *used with abrasive shield)
Housing and electronics
1HT Standard housing, transmitter electronics, HART communications
2HT Integral autocal, transmitter electronics, HART communications
4FF Integral autocal, transmitter electronics, Fieldbus communications
5DR Standard housing, direct replacement, no electronics
6DRY Standard housing, direct replacement, YEW electronics
Mounting plate
00 None
04 New installation - square weld plate with ANSI 2 in. - 150# studs & flange (2.5
in. process hole required)
05 New installation - square weld plate with DIN studs and flange (2.5 in. process
hole required)
06 New installation - variable insertion mount; abrasion resistant probe only
07 New installation - variable insertion mount; mounted to existing OXT/WC
abrasive shield mounts; abrasion resistant probe only
08 Adapter to existing ANSI 3 in. 150# flange
09 Adapter to existing ANSI 4 in. 150# flange
10 Adapter to existing ANSI 6 in. 150# flange
11 Adapter to existing ANSI 3 in. 300# flange
12 Adapter to existing ANSI 4 in. 300# flange
Reference Manual 11
Description and specifications
99 Special adapter - provide existing flange dimensions, including thru-hole di-
Manual calibration accessories
00 None
01 Calibration and reference gas flowmeters and reference regulator/filter diffus-
02 Calibration/reference panel
Stoichiometer function -FOUNDATION Fieldbus only (For HART versions, order this feature
with Rosemount 6888Xi Electronics)
0 No
1 Yes
Programmable reference function - FOUNDATION Fieldbus only (For HART versions, order
this feature with Rosemount 6888Xi Electronics)
0 No
1 Yes
Rosemount 6888A Product Matrix (continued)Table 1-2:
ameter
er
1.7
Extended temperature reference function - FOUNDATION Fieldbus only (For HART versions,
order this feature with Rosemount 6888Xi Electronics)
0 No
1 Yes
Diffuser warning function - FOUNDATION Fieldbus only (For HART versions, order this feature
with Rosemount 6888Xi Electronics)
0 No
1 Yes
(1) Probes supplied with flanges with dual ANSI/DIN hole pattern.
Rosemount 6888Xi product matrix
Compare the configuration matrix below to the model number on the probe tag to
confirm the features present in this specific probe.
Model
6888Xi Advanced Electronics
Remote type
1OXY Single channel O
2OXY Single channel O2 with flame safety interlock for heater
3OXY Dual channel O
4OXY Single channel O2 with traditional architecture for 120 V probes
Product description
2
2
(1)
12 Rosemount 6888A
Description and specifications
Mounting
00 No Hardware
01 Panel mount kit with gasket
02 2 in. pipe/wall mount kit
Cable
00 No cable
10 6 m (20 ft) cable, use with traditional architecture probe only
11 12 m (40 ft) cable, use with traditional architecture probe only
12 18 m (60 ft) cable, use with traditional architecture probe only
13 24 m (80 ft) cable, use with traditional architecture probe only
14 30 m (100 ft) cable, use with traditional architecture probe only
15 45 m (150 ft) cable, use with traditional architecture probe only
16 60 m (200 ft) cable, use with traditional architecture probe only
Stoichiometer function for O
2
00 No
01 Single channel
02 Dual channel
Programmable reference function for O
2
00 None
01 Single channel
02 Dual channel
Extended Temperature Function for O
2
00 None
01 Single channel
02 Dual channel
Plugged diffuser diagnostics
00 None
01 Single channel
02 Dual channel
(1) The Rosemount 6888Xi does not support World Class 44v probes.
Reference Manual 13
Description and specifications
The X-STREAM Xi will support World Class 44v probes.
1.8 Transmitter/DR probe specifications
Measurement SpecificationsTable 1-3:
Net O2 range Variable 0 - 10% to 0 - 50%
(Xi electronics off 0 - 50% O2 range)
Accuracy in oxidizing condition ±0.75% of reading or 0.05% O2, whichever is greater
Lowest detectable limit 0.02% O
Process temperature effect Less than 0.05% O2 from 100 to 700 °C (212 to 1292 °F)
System speed of response to calibration gas Initial response in less than 3 seconds, T∞ in less than 8
seconds. Response to process gas changes vary depending
on velocity and particulate loading of the diffuser.
Calibration validity Presentation of calibration gases matches the bottle value
to within ±0.02% O2.
Accuracy in reducing conditions (requires stoichiometer
feature)
System response in reducing conditions (requires stoichiometer feature)
±10% of reading or 0.1% O2, whichever is greater
Going from oxidizing to reducing -T90 in 120 seconds
Going from reducing to oxidizing -T90 in 30 seconds
2
Environmental specificationsTable 1-4:
Transmitter probe Process-wetted materials are 316L or 304 stainless.
Process temperature limits 0 to 705 °C (32 to 1300 °F)
550 to 825 °C (1022 to 1517 °F) with Xi heaterless operation
(1)
feature
Transmitter electronics housing Low copper aluminum Type 4X/IP66 with reference air ex-
haust port piped to clean, dry area
Ambient temperature limits
-40 to 70 °C (-40 to 158 °F), transmitter
-40 to 85 °C (-40 to 185 °F) as measured by electronics
-40 to 90 °C (-40 to 194 °F), DR probe
Probe electronics ambient temperature limits -40 to 70 °C (-40 to 158 °F)
Temperature limit as measured inside probe electronics -40 to 85 °C (-40 to 185 °F)
DR probe, no electronics inside, ambient temperature limits
Optional Xi electronics
Materials NEMA 4X, polycarbonate material
-40 to 90 °C (-40 to 194 °F)
14 Rosemount 6888A
Description and specifications
Environmental specifications (continued)Table 1-4:
General purpose certifications
Xi ambient temperature limits -20 to 50 °C (-4 to 122 °F)
Xi temperature limits as measured inside the electronics
-20 to 70 °C (-4 to 158 °F)
housing
(1) Reduced cell life can be expected if operated continously at temperatures above 705 °C (1300 °F). Optional bypass and jacket
accessories permit operation to 1050 °C (1922 °F).
Installation specifications - probeTable 1-5:
Probe mounting flange Vertical or horizontal - 2 in. 150# (121 m (4.75 in.) bolt cir-
cle)
Note
Flanges are flat-faced and for mounting only. Flanges are
not pressure-rated. A 2.5-in. diameter hole in the process
is required.
Spool piece PN 3D39761G02 is available to offset probe
electronics housing from hot duct work.
Many adapter flanges are available to mate to existing
flanges.
Probe lengths and approximate shipping weights
457 mm (18 in.) package 7.3 kg (16 lb)
0.91 m (3 ft) package 9.5 kg (21 lb)
1.83 m (6 ft) package 12.2 kg (27 lb)
2.74 m (9 ft) package 15.0 kg (33 lb)
3.66 m (12 ft) package 17.7 kg (39 lb)
Reference air (optional) 2 scfh (1 L/min), clean, dry, instrument-quality air (20.95%
O2), regulated to 5 psi (34 kPa)
Calibration Semi-automatic or automatic
Calibration gases 0.4% O2 and 8% O2, balance N2recommended. Instrument
air may be used as a high cal gas but is not recommended.
100% nitrogen cannot be used as the low cal gas.
Calibration gas line 91 m (300 ft) maximum length
Calibration gas flow 5 scfh (2.5 L/min)
Heater electrical power 120/140 Vac ± 10%, 50/60 Hz, 260/1020 VA max, 1/2-in. -
14 NPT conduit ports
Traditional architecture cable 61 m (200 ft) maximum length
Power consumption of probe heater 776 VA maximum during warm-up
Reference Manual 15
Description and specifications
Installation specifications - probe (continued)Table 1-5:
4-20 mA/HART loop power 12-30 Vdc (loop power from control room or Rosemount
6888Xi)
Installation Specifications: Rosemount 6888Xi with Transmitter ProbeTable 1-6:
Electrical power of optional Xi electronics 120/240 V ±10%, 50/60 Hz
Power consumption of Xi 10 watts maximum
Xi alarm relays 2 provided - 2 amps, 30 Vdc
Xi optional loss of flame contact Removes heater power
Electrical noise Meets EN 61326, Class A
Traditional architecture cable 61 m (200 ft) maximum length
Transmitter electrical 4-20 mA power 12 - 42 Vdc (loop-powered from the control room or from
the Xi box)
Table 1-7:
Installation Specifications for Traditional Architecture Rosemount 6888Xi for use with DR or
other Probe
Electrical power for Xi 120/240 V ±10%, 50/60 Hz
Power consumption of Xi 12 VA maximum or 1020 VA maximum with traditional ar-
chitecture, 120 V probes
450 VA maximum with traditional architecture 44 V
probes
Alarm relay outputs Two provided - 2 amperes, 30 Vdc, Form-C
Optional loss of flame input Internally powered input to remove heater power actuated
via dry contact output from probe of flame device.
Emerson has satisfied all obligations coming from the European legislation to harmonize
the product requirements in Europe.
16 Rosemount 6888A
2 Install
WARNING!
Before installing this equipment, read the Essential Instructions at the front of this Reference
Manual. Failure to follow safety instructions could result in serious injury or death.
WARNING!
ELECTRIC SHOCK
Install all protective equipment covers and safety ground leads after installation. Failure to
install covers and ground leads could result in serious injury or death.
WARNING!
HAZARDOUS AREAS
The Rosemount™ 6888A O2 Transmitter can be installed in general purpose areas only. Do not
install the transmitter in hazardous areas or in the vicinity of flammable liquids.
Install
CAUTION!
EQUIPMENT DAMAGE
If external loop power is used, the power supply must be a safety extra low voltage (SELV)
type.
Reference Manual 17
Install
2.1 System considerations
NOTICE
Plug all unused ports on the Rosemount 6888A probe housing with suitable fittings.
A typical system installation for a Rosemount 6888A with integral electronics is shown in
Figure 2-1.
Typical system installationFigure 2-1:
A. Gases
B. Duct
C. Adapter plate and flange
D. Instrument air supply (reference air)
E. Pressure regulator
F. Flowmeter
G. Calibration gas
H. Line voltage
I. 4 to 20 mA signal
J. Rosemount 6888Xi Advanced Electronics (optional)
K. Stack
A source of instrument air is required at the transmitter for reference air flow [2.0 scfh
(1.0 L/min)]. Since the unit is equipped with an in place calibration feature, you can make
provisions to permanently connect calibration gas bottles to the transmitter.
18 Rosemount 6888A
Install
If the calibration gas bottles will be permanently connected, install a check valve next to
the calibration fittings on the probe. This check valve is to prevent breathing of the
calibration gas line and subsequent flue gas condensation and corrosion. The check valve
is in addition to the stop valve on the calibration gas bottles or the solenoid valves in the
Rosemount SPS 40001B or Rosemount IMPS 4000.
If the Rosemount 6888Xi Advanced Electronics option is not used, the 4 to 20 mA signal
from the probe will be loop-powered from the DCS. A 375/475 Field Communicator or
AMS is required to set up and operate the probe.
The optional Rosemount 6888Xi enhanced interface communicates with the probe
transmitter electronics via HART® communications riding on to the 4 to 20 mA signal
coming from the transmitter. If using the 375/475 Field Communicator, connect it to the 4
to 20 mA signal loop between the Rosemount 6888Xi and the control room or data
acquisition system. Connecting the 375/475 Field Communicator between the transmitter
and Rosemount 6888Xi will cause communication errors and affect system operation.
NOTICE
The transmitter electronics is rated Type 4X and IP66 and is capable of operation at
temperatures from -40 to 85 °C (-40 to 185 °F). Retain the packaging in which the Rosemount
6888A arrived from the factory in case any components are to be shipped to another site. This
packaging has been designed to protect the product.
2.2 Mechanical installation
Most combustion processes run only slightly negative or positive in pressure, so that the
probe flange is for mechanical mounting only. The probe is not rated for high pressures. If
this is a new installation, a weld plate for welding to the flue gas duct can be supplied.
WARNING!
ELECTRIC SHOCK
Install all protective equipment covers and safety ground leads after installation. Failure to
install covers and ground leads could result in serious injury or death. The Rosemount 6888A
O2 transmitter can be installed in general purpose areas only. Do not install the transmitter or
the Rosemount 6888Xi in hazardous areas or in the vicinity of flammable liquids.
Reference Manual 19
Install
2.2.1 Install probe
Complete the following steps to install the Rosemount 6888A O2 probe.
1. Ensure all components are available to install the Rosemount 6888A O2 probe.
Refer to the probe installation details in Figure 2-1. If using the optional ceramic or
Hastelloy diffusion element, the vee deflector must be correctly oriented.
2. Before inserting the Rosemount 6888A probe, check the direction of gas flow in the
duct. Orient the vee deflector so the apex points upstream toward the flow. See
Figure 2-2.
Orienting the Optional Vee DeflectorFigure 2-2:
A. Gas flow direction
B. Vee deflector
C. Diffusion element
D. Setscrew
E. Vee deflector
F. Filter
G. Apex
3. If using the standard square weld plate or an optional flange mounting plate, weld or
bolt the plate onto the duct.
20 Rosemount 6888A
Install
Figure 2-3:
Rosemount 6888A Probe with Standard Terminations/Electronic
Housing
Note
All dimensions are in inches with millimeters in parentheses.
Rosemount 6888A Integral Autocal HousingFigure 2-4:
A. Dimension
B. Dimension
C. Hastelloy diffuser
D. Ceramic diffuser
Note
All dimensions are in inches with millimeters in parentheses.
Reference Manual 21
Install
Rosemount 6888A Integral Autocal Housing Close-upFigure 2-5:
A. Dimension
B. Dimension
C. Calibration gas 1/4 tube fittings 5.0 SCFH (2.4 L/min) 20 PSI (138 kPa)
D. #10 socket head cap screw (external ground)
E. 1/2 NPT conduit connection (power, signal)
F. Reference gas 1/4 tube fitting 2.0 SCFH (1.0 L/min) 20 PSI (138 kPa)
G. Reference air vents
Note
All dimensions are in inches with millimeters in parentheses.
Removal/InstallationTable 2-1:
Probe length
457 mm (18 in.) probe 409 mm (16.1in.) 401 mm (15.77 in.) 490 mm (19.26 in.)
0.91 m (3 ft) probe 826 mm (33.52 in.) 1182 mm (46.6 in.) 1271 mm (50.1 in.)
1.83 m (6 ft) probe 1740 mm (68.52 in.) 2097 mm (82.6 in.) 2186 mm (86.1 in.)
2.74 m (9 ft) probe 2655 mm (104.52 in.) 3011 mm (118.6 in.) 3100 mm (122.1 in.)
3.66 m (12 ft) probe 3569 mm (140.52 in.) 3926 mm (154.6 in.) 4015 mm (158.1 in.)
(1) Add 96 mm (3.8 in.) to Dim A and Dim B for probe with ceramic or Hastelloy diffuser.
(1)
Dim A insertion depth
Dim B removal envelope
standard housing
Dim B removal envelope
accessory housing
The through hole diameter in the stack or duct wall and refractory material must be
at least 63.5 mm (2-1/2 in.)
4. Insert probe through the opening in the mounting flange and bolt the unit to the
flange.
22 Rosemount 6888A
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