Instruction Manual
748003-N
November 2002
Model 868
Non-Dispersive Infrared Analyzer
http://www.processanalytic.com
ESSENTIAL INSTRUCTIONS
READ THIS PAGE BEFORE PROCEEDING!
Rosemount Analytical 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
normal specifications. The following instructions MUST be adhered to and integrated into your
safety program when installing, using, and maintaining Rosemount Analytical 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.
to ensure they continue to operate within their
• Read all instructions
prior to installing, operating, and servicing the product.
• If you do not understand any of the instructions, contact your Rosemount Analytical
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 your 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 Rosemount. 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 persons, to prevent electrical shock
and personal injury.
.
The information contained in this document is subject to change without notice.
Teflon® is a registered trademark of E.I. duPont de Nemours and Co., Inc.
Alconox is a registered trademark of Alconox, Inc.
SNOOP® is a registered trademark of NUPRO Co.
Emerson Process Management
Rosemount Analytical Inc.
Process Analytic Division
1201 N. Main St.
Orrville, OH 44667-0901
T (330) 682-9010
F (330) 684-4434
e-mail: gas.csc@EmersonProcess.com
http://www.processanalytic.com
Model 868
Instruction Manual
748003-N
November 2002
TABLE OF CONTENTS
PREFACE...........................................................................................................................................P-1
Definitions ...........................................................................................................................................P-1
Safety Summary .................................................................................................................................P-2
General Precautions For Handling And Storing High Pressure Gas Cylinders .................................P-4
Documentation....................................................................................................................................P-5
Condensed Startup And Calibration Procedure .................................................................................P-6
1.0 DESCRIPTION AND SPECIFICATIONS..............................................................................1-1
1-1 Overview................................................................................................................................1-1
1-2 Specifications.........................................................................................................................1-2
2.0 INSTALLATION ....................................................................................................................2-1
2-1 Unpacking..............................................................................................................................2-1
2-2 Location .................................................................................................................................2-1
2-3 Facility Preparation................................................................................................................2-1
a. Power Requirements ......................................................................................................2-1
b. Gas Connections.............................................................................................................2-1
2-4 Outline And Mounting Dimensions ........................................................................................2-1
2-5 Power Connections ...............................................................................................................2-1
a. Voltage Select Board ......................................................................................................2-1
b. Heater Voltage Select.....................................................................................................2-2
c. Fuse Select Panel...........................................................................................................2-2
2-6 Recorder Connection.............................................................................................................2-2
2-7 Remote Range ......................................................................................................................2-2
2-8 Sample Inlet/Output Connections..........................................................................................2-2
2-9 Calibration Gas Requirements ..............................................................................................2-2
2-10 Sample Handling System ......................................................................................................2-3
2-11 Leak test ................................................................................................................................2-3
2-12 Sample Flow Rate .................................................................................................................2-3
2-13 Differential Analysis With Flow Through Reference Cell.......................................................2-4
3.0 DETAILED STARTUP...........................................................................................................3-1
3-1 Startup ...................................................................................................................................3-1
3-2 Current Source Adjustment ...................................................................................................3-1
3-3 Display Readouts Using CHECK Switch...............................................................................3-1
3-4 RANGE Switch Position (O.T.) Oscillator Tune.....................................................................3-2
3-5 Range Switch ........................................................................................................................3-2
3-6 Time Constant Selection .......................................................................................................3-2
3-7 Preamp Gain Adjustment ......................................................................................................3-3
3-8 Source Balance Shutter Adjustment .....................................................................................3-3
3-9 Zero Adjust ............................................................................................................................3-3
3-10 span adjustment ....................................................................................................................3-3
3-11 Calibration without linearizer .................................................................................................3-4
3-12 Calibration with Linearizer .....................................................................................................3-4
Rosemount Analytical Inc. A Division of Emerson Process Management Contents i
Instruction Manual
748003-N
November 2002
4.0 OPERATION .........................................................................................................................4-1
4-1 Routine Operation .................................................................................................................4-1
4-2 Recommended Calibration Frequency..................................................................................4-1
4-3 Shutdown...............................................................................................................................4-1
5.0 THEORY................................................................................................................................5-1
5-1 Overview................................................................................................................................5-1
5-2 Detection System ..................................................................................................................5-1
5-3 Electronic Circuitry.................................................................................................................5-2
a. Oscillator Circuit Board and Associated Elements of Amplitude-Modulation Circuit......5-2
b. Functioning of Modulation System in TUNE Mode.........................................................5-2
c. Functioning of Modulation System in Operating Mode...................................................5-4
d. Radio-Frequency Demodulator.......................................................................................5-4
e. Filter/Rectifier Board and Associated Elements .............................................................5-4
f. Remote Range Control ...................................................................................................5-6
g. Source Driver ..................................................................................................................5-7
h. Analog Signal Path..........................................................................................................5-8
5-4 Chopper Driver ......................................................................................................................5-9
a. Recorder Output..............................................................................................................5-9
b. Temperature Control.......................................................................................................5-9
c. Power Supply ..................................................................................................................5-9
Model 868
6.0 SERVICE AND TROUBLESHOOTING ................................................................................6-1
6-1 Cell Removal and Replacement............................................................................................6-2
6-2 Cell Cleaning .........................................................................................................................6-7
6-3 Cell Desiccant........................................................................................................................6-7
6-4 Source Housing Removal......................................................................................................6-7
a. Source Removal..............................................................................................................6-7
b. Chopper Motor Replacement..........................................................................................6-7
6-5 Detector Removal..................................................................................................................6-7
6-6 Troubleshooting Procedures .................................................................................................6-8
a. Chopper Drive.................................................................................................................6-8
b. Temperature Controller...................................................................................................6-8
c. Source Drive ...................................................................................................................6-8
d. Voltage Checks...............................................................................................................6-8
7.0 REPLACEMENT PARTS ......................................................................................................7-1
7-1 Circuit Board Replacement Policy.........................................................................................7-1
7-2 Recommended Replacement Parts ......................................................................................7-1
7-3 Linearization Kit .....................................................................................................................7-5
a. Installation.......................................................................................................................7-5
b. Electrical Connections.....................................................................................................7-5
c. Setup...............................................................................................................................7-5
d. Troubleshooting and Repair............................................................................................7-6
e. Board Functions (Linearizer)...........................................................................................7-6
f. Linearized Analyzer.........................................................................................................7-7
8.0 RETURN OF MATERIAL ......................................................................................................8-1
8-1 Return Of Material .................................................................................................................8-1
8-2 Customer Service ..................................................................................................................8-1
8-3 Training..................................................................................................................................8-1
ii Contents Rosemount Analytical Inc. A Division of Emerson Process Management
Model 868
Figure 2-1.
Figure 2-2. Heater Voltage Section.......................................................................................... 2-2
Figure 3-1. Source Current Adjustment ................................................................................... 3-1
Figure 3-2. Front Panel Controls.............................................................................................. 3-2
Figure 5-1. Functional Diagram of Detection System .............................................................. 5-1
Figure 5-2. Signal Circuitry....................................................................................................... 5-3
Figure 5-3. Modulation System ................................................................................................ 5-5
Figure 5-4. Remote Range Select Circuit ................................................................................ 5-6
Figure 5-5. Automatic Range Select Circuit............................................................................. 5-7
Figure 6-1. Configuration Assembly – Part 1 ........................................................................... 6-2
Figure 6-2. Configuration Assembly – Part 2 ........................................................................... 6-3
Figure 6-3. Configuration Assembly – Part 3 ........................................................................... 6-4
Figure 6-4. Configuration Assembly – Part 4 ........................................................................... 6-5
Figure 6-5. Motor/Source Assembly......................................................................................... 6-6
Figure 7-1. Functional Diagram of Linearizer Board ................................................................ 7-9
Figure 7-2. Installation of Linearizer Board .............................................................................. 7-9
Figure 7-3. Linearizer Setup Switches ................................................................................... 7-10
Figure 7-4. Block Diagram, Model 868 Electronics................................................................ 7-10
Figure 7-5. Behavior of Instrument within Block Diagram...................................................... 7-11
Figure 7-6. Example Showing Relationship Between Range 2 and Range 1 Responses
Figure 7-7. Example Showing Relationship Between Range 2 and Range 1 Responses
Instruction Manual
748003-N
November 2002
LIST OF ILLUSTRATIONS
Line Voltage Selection ........................................................................................... 2-2
When Sensitivity of Range 2 is 100/60 Times Sensitivity of Range 1................. 7-12
When Sensitivity of Range 3 is 100/37 Times Sensitivity of Range 1................. 7-12
LIST OF TABLES
Table P-1. Range Switch Settings........................................................................................... P-6
Table 2-1. Purging Time at Atmospheric Sample Pressure.................................................... 2-4
Table 3-1. Range Switch Readings ........................................................................................ 3-1
Table 7-1. Parts List - Configuration/Application 10, 12, 13, 18, 22, 23, 38, 42, 43 ............... 7-2
Table 7-2. Parts List – Configuration/Application 26............................................................... 7-3
Table 7-3. Parts List - Configuration/Application 11, 21, 31, 36, 41, 44, 54, 56 ..................... 7-4
Table 7-4. Linearized Configuration Selection........................................................................ 7-8
Rosemount Analytical Inc. A Division of Emerson Process Management Contents iii
Instruction Manual
748003-N
November 2002
Model 868
DRAWINGS
619803 Schematic Diagram, Oscillator Board
619839 Schematic Diagram, Front Panel Display
620126 Schematic Diagram, Power Supply
620249 Schematic Diagram, Filter/Rectifier Board
620363 Pictorial Wiring Diagram, Model 868
620391 Schematic Diagram, Recorder Range Output
620474 Installation Drawing, Model 868
622190 Schematic Diagram, Linearizer Board
(LOCATED IN REAR OF MANUAL)
iv Contents Rosemount Analytical Inc. A Division of Emerson Process Management
Instruction Manual
Model 868
November 2002
PREFACE
The purpose of this manual is to provide information concerning the components,
functions, installation and maintenance of the Model 868 Non-Dispersive Infrared
Analyzer.
Some sections may describe equipment not used in your configuration. The user should
become thoroughly familiar with the operation of this module before operating it. Read
this instruction manual completely.
DEFINITIONS
The following definitions apply to DANGERS, WARNINGS, CAUTIONS and NOTES found throughout
this publication.
748003-N
DANGER .
Highlights the presence of a hazard which will cause severe personal injury, death, or substantial
property damage if the warning is ignored.
WARNING .
Highlights an operation or maintenance procedure, practice, condition, statement, etc. 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. If not
strictly observed, could result in damage to or destruction of equipment, or loss of effectiveness.
NOTE
Highlights an essential operating procedure,
condition or statement.
Rosemount Analytical Inc. A Division of Emerson Process Management Preface P-1
Instruction Manual
748003-N
November 2002
SAFETY SUMMARY
If this equipment is used in a manner not specified in these instructions, protective systems may be
impaired.
AUTHORIZED PERSONNEL
To avoid explosion, loss of life, personal injury and damage to this equipment and on-site
property, all personnel authorized to install, operate and service the this equipment should be
thoroughly familiar with and strictly follow the instructions in this manual. SAVE THESE INSTRUCTIONS.
DANGER.
ELECTRICAL SHOCK HAZARD
Model 868
Do not operate without doors and covers secure. Servicing requires access to live parts which can
cause death or serious injury. Refer servicing to qualified personnel.
For safety and proper performance this instrument must be connected to a properly grounded
three-wire source of power.
WARNING
POSSIBLE EXPLOSION HAZARD
This instrument is not designed for analysis of flammable gas samples. If flammable gas samples
are introduced, internal leakage could create a flammable mixture which could result in an
explosion.
WARNING .
PARTS INTEGRITY
Tampering or unauthorized substitution of components may adversely affect safety of this product.
Use only factory documented components for repair.
P-2 Preface Rosemount Analytical Inc. A Division of Emerson Process Management
Instruction Manual
Model 868
WARNING.
HIGH PRESSURE GAS CYLINDERS
This instrument requires periodic calibration with a known standard gas. See Sections 2-9 on page
2-2, 3-11 on page 3-4 and 3-12 on page 3-4. See also General Precautions for Handling and Storing
High Pressure Gas Cylinders, page P-on page 4.
WARNING.
PARTS INTEGRITY
Tampering or unauthorized substitution of components may adversely affect safety of this product.
Use only factory documented components for repair.
WARNING.
TOPPLING HAZARD
November 2002
748003-N
This instrument’s internal pullout chassis is equipped with a safety stop latch located on the left
side of the chassis. When extracting the chassis, verify that the safety latch is in its proper
(counter-clockwise) orientation.
If access to the rear of the chassis is required, the safety stop may be overridden by lifting the
latch; however, further extraction must be done very carefully to insure the chassis does not fall
out of its enclosure.
If the instrument is located on top of a table or bench near the edge, and the chassis is extracted, it
must be supported to prevent toppling.
Failure to observe these precautions could result in personal injury and/or damage to the product.
Rosemount Analytical Inc. A Division of Emerson Process Management Preface P-3
Instruction Manual
748003-N
November 2002
Model 868
GENERAL PRECAUTIONS FOR HANDLING AND STORING HIGH
PRESSURE GAS CYLINDERS
Edited from selected paragraphs of the Compressed Gas Association's "Handbook of Compressed
Gases" published in 1981
Compressed Gas Association
1235 Jefferson Davis Highway
Arlington, Virginia 22202
Used by Permission
1. Never drop cylinders or permit them to strike each other violently.
2. Cylinders may be stored in the open, but in such cases, should be protected against extremes of
weather and, to prevent rusting, from the dampness of the ground. Cylinders should be stored in the
shade when located in areas where extreme temperatures are prevalent.
3. The valve protection cap should be left on each cylinder until it has been secured against a wall or
bench, or placed in a cylinder stand, and is ready to be used.
4. Avoid dragging, rolling, or sliding cylinders, even for a short distance; they should be moved by using a
suitable hand-truck.
5. Never tamper with safety devices in valves or cylinders.
6. Do not store full and empty cylinders together. Serious suckback can occur when an empty cylinder is
attached to a pressurized system.
7. No part of cylinder should be subjected to a temperature higher than 125
never be permitted to come in contact with any part of a compressed gas cylinder.
8. Do not place cylinders where they may become part of an electric circuit. When electric arc welding,
precautions must be taken to prevent striking an arc against the cylinder.
°
F (52°C). A flame should
P-4 Preface Rosemount Analytical Inc. A Division of Emerson Process Management
Instruction Manual
Model 868
November 2002
DOCUMENTATION
The following Model 868 instruction materials are available. Contact Customer Service Center or the local
representative to order.
748003 Instruction Manual (this document)
748003-N
Rosemount Analytical Inc. A Division of Emerson Process Management Preface P-5
Instruction Manual
748003-N
November 2002
CONDENSED STARTUP AND CALIBRATION PROCEDURE
Model 868
Prior to shipment, this analyzer was subjected
to extensive factory performance testing, during
which all necessary optical and electrical adjustments were made. The following instructions are recommended for initial startup and
subsequent standardization of the analyzer. In
most cases, these simple instructions are sufficient to operate the analyzer. The detailed instructions given in Section 3 are required if the
optical bench alignment has been disturbed,
which could possible occur during shipment.
Leak Test Procedure
WARNING
POSSIBLE EXPLOSION HAZARD
This analyzer is not designed for analysis of
flammable gas samples. If flammable gas
samples are introduced, internal leakage
could create a flammable mixture which
could result in an explosion.
The following test is designed for sample pressure up to 10 psig (69 kPa).
1. Supply air or inert gas such as nitrogen at
10 psig (69 kPa) to analyzer via a flow in-
SWITCH
POSITION
0 +5 VDC 4.75 To 5.25 VDC
1 -5 VDC -4.50 To -5.10 VDC
2 +15 VDC +14.25 To 15.75 VDC
3 -15 VDC -14.25 To -15.75 VDC
4 +12 VDC +11.4 To 12.6 VDC
5 REF Voltage 2.4 To 2.6 VDC
6 + Source V1
7 - Source V1
8 Source I1
9 Preamp Out1
Analyzer is now calibrated for Range 1. If the analyzer is to be used on auxiliary Range 2 and/or Range 3,
perform the steps in Calibration of Range 2 and Calibration of Range 3 below.
FUNCTION READING
Table P-1. Range Switch Settings
dicator with a range of 0 to 250
cc/min. and set flow rate at 125
cc/min.
2. Use a suitable test liquid such as
SNOOP (PN 837 801) to detect
leaks. Cover all fittings, seals, or
possible leak sources.
3. Check for bubbling or foaming which
indicates leakage and repair as required. Any leakage must be corrected before introduction of sample
and/or application of electrical power.
Power Verification
1. Verify power switch settings are correct for available power (115 VAC or
230 VAC).
2. Apply power. Verify that heater LED
is on (decimal point of Mode display)
and that chopper LED is blinking
(decimal point of Range display).
3. Move RANGE switch to CH position
and verify per Table P-1.
1
Determined by application. See Infrared Analyzer Calibration and Data Sheet, located in the rear of this manual.
P-6 Preface Rosemount Analytical Inc. A Division of Emerson Process Management
Model 868
Instruction Manual
748003-N
November 2002
Calibration
1. Allow system to warm-up a minimum of
one hour.
2. Connect zero gas to the sample cell inlet
at the back of the analyzer. Flow the gas
at a flow rate of 500 cc/min, as read on a
flowmeter, through the analyzer for at
least two minutes. Adjust the ZERO control on front panel so meter or recorder
reads zero.
3. Connect the upscale gas to the sample
cell inlet.
a. Verify that RANGE switch is in Posi-
tion 1 (least sensitive range).
b. Flow the upscale gas appropriate for
Range 1, at a flow rate of 500 cc/min.,
through the analyzer for at least two
minutes.
c. Adjust the SPAN control on the front
panel so the display reads the desired
output. Refer to the calibration curves
in Section 8.
Calibration of Range 2
1. Place RANGE switch at Position 2.
2. Flow upscale gas appropriate to Range
2, at a flow rate of 500 cc/min., through
the analyzer for at least two minutes.
3. Adjust switches S2, S3, and S4 for desired reading. (S4 is the least sensitive
switch).
Calibration of Range 3
1. Place RANGE switch at Position 3.
2. Flow upscale gas appropriate to Range
3, at a flow rate of 500 cc/min., through
the analyzer for at least two minutes.
3. Adjust switches S5, S6, and S7 for desired reading. (S7 is the least sensitive
switch).
Time Constant Switch S9
Set switch S9 to the desired speed of response of the electronics (time constant).
The analyzer is now calibrated for all three
ranges and is ready for sample analysis.
Rosemount Analytical Inc. A Division of Emerson Process Management Preface P-7
Instruction Manual
748003-N
November 2002
Model 868
Preface Rosemount Analytical Inc. A Division of Emerson Process Management
P-8
Model 868
DESCRIPTION AND SPECIFICATIONS
1-1 OVERVIEW
The Model 868 Non-Dispersive Infrared Analyzer (NDIR) continuously determines the concentration of a particular component of interest
in a flowing mixture. The analysis is based on a
differential measurement of the absorption of infrared energy. With the proper selection of detector, optics and cells, the instrument has a
wide range of applications, subject only to the
limitation that the analysis involve the determination of a single component, which must absorb infrared energy.
Within the analyzer, two equal energy infrared
beams are directed through two parallel optical
cells, a flow-through sample cell and a sealed
reference cell. Solid-state electronic circuitry
continuously measures the difference between
the amount of infrared energy absorbed in the
Instruction Manual
748003-N
November 2002
SECTION 1
two cells. This difference is a measure of
the concentration of the component of interest in the sample. Readout is on a front
panel display with 0 to 199.9 digital display.
In addition, a +5 VDC output for a potentiometric (voltage) recorder is provided as
standard. Additional outputs (0 to 10 mV, 0
to 100 mV, 0 to 1 VDC) are available as options.
A calibration curve may be used to convert
display or recorder readings into concentration values. The analyzer may utilize an optional linearizer circuit for linear readout of
concentration values on the display and on
a recorder.
The analyzer is equipped for remote selection of ranges.
Rosemount Analytical Inc. A Division of Emerson Process Management Description and Specifications 1-1
Instruction Manual
748003-N
November 2002
1-2 SPECIFICATIONS
Repeatability.................................. 1% of fullscale
Noise ............................................. 1% of fullscale
1
Zero/Span Drift
Response Time (Electronic).......... Variable, 90% of fullscale in 0.5 to 5 seconds, field selectable
Sensitivity ...................................... 500 p/10
Sample Cell Length ....................... 0.04 inches (1mm) to 9.5 inches (24mm)
Materials in Contact with Sample
Windows .............................. Sapphire, quartz, Irtran
Cells.....................................Gold-plated glass or stainless steel
Tubing..................................FEP Teflon
Fittings ................................. 316 stainless steel
O-rings .................................Viton-A
Sample Flow Rate ......................... Nominal 500 to 1000 cc/min.
Sample Pressure........................... Maximum 10 psig (69 kPa)
Ambient Temperature Range........ 50 to 104°F (10 to 40°C)
Analog Output
Standard .............................. 0 to 5 VDC
Optional ...............................0 to 10 mV, 0 to 100 mV, 0 to 1 VDC (selectable)
Linearization .................................. Optional microprocessor based
Power Requirements..................... 115/230 VAC ±10%; 50/60 Hz ±3%; 115 W
Enclosure....................................... General purpose for installation in weather protected area
Dimensions.................................... 8 11/16 inches (220 mm) H
Weight ........................................... 32 lbs (15 kg)
Shipping Weight ............................ Approximately 46 pounds (21 kg)
1
Performance specifications based on an ambient temperature variation of less than 20°F (11°C) per hour.
............................. ±1% of fullscale per 24 hours
6
fullscale carbon monoxide 200 p/10
dioxide
19 inches (483 mm) W
16 inches (406 mm) D (with handles)
6
Model 868
fullscale carbon
Description and Specifications Rosemount Analytical Inc. A Division of Emerson Process Management
1-2
Model 868
Instruction Manual
748003-N
November 2002
SECTION 2
INSTALLATION
2-1 UNPACKING
Carefully examine the shipping carton and contents for signs of damage. Immediately notify
the shipping carrier if the carton or its contents
are damaged. Retain the carton and packing
material until the instrument is operational.
2-2 LOCATION
Preferably the analyzer should be mounted near
the sample stream to minimize sample transport
time. Of two or more alternative installation
sites, select the one subject to the least vibration.
The analyzer must be installed in a weatherprotected, non-hazardous location.
2-3 FACILITY PREPARATION
a. Power Requirements
115 or 230 VAC ±10% single phase
47 to 53 or 57 to 63 Hz
Less than 115 watts
b. Gas Connections
Sample and reference IN and OUT lines are
¼ inch tube.
2-4 OUTLINE AND MOUNTING DIMENSIONS
The Model 868 has three mounting variations:
• Panel mount
• Rack mount (Standard RETMA 19 inch)
• Table mount
Refer to installation drawing 620474 in the
rear of this manual.
General Notes for Installation
• General purpose enclosure
• 3-prong, six foot power cord supplied
with analyzer
2-5 POWER CONNECTIONS
WARNING
ELECTRICAL SHOCK HAZARD
For safety and proper performance, this
analyzer must be connected to a properly grounded 3-wire source of electrical
supply.
CAUTION
Before applying power, perform the Voltage Select procedure below.
Rosemount Analytical Inc. A Division of Emerson Process Management Installation 2-1
a. Voltage Select Board
The voltage select board is located in
the power receptacle on the rear panel.
Check that line voltage and circuit board
to insure that desired voltage is face up
on trailing edge of board as it is inserted
(Figure 2-1 on page 2-2).
Instruction Manual
748003-N
November 2002
110–115 VAC
115–130 VAC
b. Heater Voltage Select
The heater voltage select switch is located
inside the chassis in the lower right corner
of the power supply board. Slide switch to
position of desired voltage (Figure 2-2
below).
115V
Figure 2-2. Heater Voltage Select
c. Fuse Select Panel
The fuse select panel is located on the rear
panel. Select the appropriate amperage:
207-230 VAC
230-254 VAC
Figure 2-1. Line Voltage Selection
2-7 REMOTE RANGE
230V
2-8 SAMPLE INLET/OUTPUT CONNECTIONS
Model 868
• Input impedance greater than 5K ohms
The remote range connections are made to
the rear panel. See drawings 620474 and
620126.
• Maximum distance remote to analyzer –
1000 feet (305 meters)
• Remote cable – minimum 20 gauge
(customer supplied). Refer to Section 53f on page 5-6.
Sample inlet and outlet connections are located on the rear panel. This instrument is
intended for atmospheric pressure operation only. Vent must go to atmosphere.
Connections are ¼ inch tubing.
230 VAC = 0.5 amp
115 VAC = 1.0 amp
2-6 RECORDER CONNECTION
The recorder connections are made to the rear
panel at TB2. See drawings 620474 and
620126.
• Maximum distance recorder to analyzer –
1000 feet (305 meters)
• Recorder cable – minimum 20 gauge
shielded (customer-supplied)
Installation Rosemount Analytical Inc. A Division of Emerson Process Management
2-2
2-9 CALIBRATION GAS REQUIREMENTS
Analyzer calibration consists of setting a
zero point and one or more upscale points.
All applications require a zero standard gas
to set the zero point on the display or recorder chart. If the factory Calibration and
Data Sheet (in the rear of this manual)
specifies the background gas, use it as the
zero gas. If background gas is not specified, use dry nitrogen for the zero gas.
Model 868
Instruction Manual
748003-N
November 2002
2-10 SAMPLE HANDLING SYSTEM
Many different sample handling systems are
available, either completely assembled or as
loose components. The type used depends on
the requirements of the particular application
and the preferences of the individual user.
Typically, the sample handling system incorporates such components as pumps, valves to
permit selection of sample, zero standard, or
upscale standard gas; needle valve in sampleinlet line for flow adjustment; flowmeter for flow
measurement and/or indication of flow stoppage; and filter(s) to remove particulate matter.
2-11 LEAK TEST
DANGER
POSSIBLE EXPLOSION HAZARD
This instrument is not designed for analysis
of flammable gas samples. If flammable gas
samples are introduced, internal leakage
may result creating a flammable mixture
which could result in an explosion.
2-12 SAMPLE FLOW RATE
For best results, the sample flow rate must
be in the range of 1 to 2 SCFH (500 to 1000
cc/min.). A subnormal flow rate will result in
undesirable time lag.
Assume that two cell columns are required
to flush any cell. Table 2-1, on page 2-4,
indicates approximate flushing time at atmospheric sampling pressure, i.e., the outlet of the cell venting to a atmosphere for
various cell lengths.
Flushing time is inversely proportional to
flow rate.
The primary effect of flow rate, other than
flushing time, is cell pressure. Due to the
restriction of the exit tubing, increasing flow
rate increases sample pressure in the cell.
For a 9-inch (232 mm) cell venting to atmosphere, the cell pressure rises from 0
psig (0 kPa) at no flow, essentially linearity,
by 1 mm Hg per CFH flow up to at least 20
CFH (10 L/min.).
The following procedure is designed for sample
pressure up to 10 psig (69 kPa).
1. Supply air or inert gas such as nitrogen at
10 psig (69 kPa) to analyzer via a flow indicator with a range of 0 to 250 cc/min.
2. Set flow rate at 125 cc/min.
3. Use a suitable test liquid such as SNOOP
(PN 837801) to detect leaks. Cover all
fittings, seals and all sources of possible
leaks.
4. Check for bubbling or foaming which indicates leaks.
5. Correct any leakage for introduction of
sample and/or application of electrical
power.
At 7.5 to 8.0 CFH (3.8 to 4 L/min.), therefore, the pressure is increased by about 1%,
and the output signal is thereby increased
by about the same 1% over static conditions. In all cases, the effect of pressure on
readout is eliminated if the same flow rate is
used for the measured sample as well as
for the zero gas and span gas.
It should be noted that at higher flow rates,
because of increase in sample cell pressure, the non-linearity of the calibration
curve increases. Therefore, if higher flow
rates are required, the calibration curve
should be redrawn at these same flow
rates.
At 2 CFH (1 L/min.) gaseous sample temperatures are equilibrated to instrument
temperature regardless of stream temperature. At extremely high flow rates, this may
not be true, but no such effect has been
noted up to 18 CFH (9 L/min.).
Rosemount Analytical Inc. A Division of Emerson Process Management Installation 2-3
Instruction Manual
748003-N
November 2002
Model 868
Cell Length
mm inch
4 .157 1.14 12 2 sec
8 .315 2.28 13 2 sec
16 .630 4.56 16 2 sec
32 1.25 9.12 20 2 sec
64 2.52 18.24 25 3 sec
128 5.03 36.48 44 3 sec
232 9.13 66.12 73 6 sec
2-13 DIFFERENTIAL ANALYSIS WITH FLOW
THROUGH REFERENCE CELL
In some applications the analyzer is used to
measure the difference between the concentration of the component of interest in two sample
streams. If so, the reference side of the analyzer, as well as the sample side, utilizes a flow-
Cell Volume (CC)
(Without inlet tube)
Table 2-1. Purging Time at Atmospheric Sample Pressure
Total Volume (CC)
(Cell with inlet tube)
through cell. The sample cell receives the
sample stream, which contains the higher
concentration of the component of interest.
The reference cell receives the stream containing the lower concentrations of this
component.
Time For Two Volumes @ 2
Scfh (1L/min)
@ 750 mm Hg
Installation Rosemount Analytical Inc. A Division of Emerson Process Management
2-4
Model 868
3-1 STARTUP
During final factory test all controls and adjustments were set so that all field adjustments can be accomplished using the front
panel display and the controls located behind the door in the front panel.
Instruction Manual
748003-N
November 2002
SECTION 3
DETAILED STARTUP
3. Move CHECK switch to Positions 6 and
7. Position 7 shows the negative output
driver signal in volts. Position 6 shows the
positive output driver signal. These
should be within 50 mV of each other.
3-2 CURRENT SOURCE ADJUSTMENT
Refer to Figure 3-1 below.
1. RANGE switch in CH position.
2. CHECK switch in Position 8. This displays the current through the
sources. The reading must be multiplied by 100 to obtain the current in
milliamps. Clockwise adjustment of
R5 will increase the value. Counterclockwise will decrease the value.
Adjust for desired current as indicated on data sheet for the application.
3-3 DISPLAY READOUTS USING CHECK SWITCH
CHECK SWITCH
POSITION
0 +5 VDC 4.75 to 5.25 VDC
1 -5 VDC -4.5 to -5.1 VDC
2 +15 VDC +14.25 to 15.75 VDC
3 -15 VDC -14.25 to -15.75 VDC
4 +12 VDC +11.4 to 12.6 VDC
5 REF Voltage 2.4 to 2.6 VDC
6 + Source V See note
7 - Source V See note
8 Source I See note
9 Preamp Out voltage will vary
Note: Determined by application. See Factory Data Sheet in the rear of this manual.
Table 3-1. Range Switch Readings
FUNCTION READING
Figure 3-1. Source Current Adjustment
R52 R5
SOURCE ADJUSTMENT ADC SPAN
FRONT
PANEL
Rosemount Analytical Inc. A Division of Emerson Process Management Startup 3-1
Instruction Manual
748003-N
November 2002
Model 868
3-4 RANGE SWITCH POSITION (O.T.) OSCILLA-
TOR TUNE
Refer to Figure 3-2 below.
1. This procedure is not necessary on a
routine basis. Record initial number and
check for any change exceeding ±5%.
To check the tuning, turn the RANGE
Switch to O.T.
2. Adjust coil (located on right side of detector housing) clockwise until a maximum reading is obtained on the
display.
3. Adjust coil counterclockwise until unit
reads 75% and 80% of the maximum
value. This positions the system for correct operation.
3-5 RANGE SWITCH
REMOTE Position
Allows the range selection unit to be controlled from a remote source.
3-6 TIME CONSTANT SELECTION
Set by switch (S9) located behind the front
panel door. This switch selects speed of response of the electronics. The base line will
be noisier on 1/2-second response than on
2.5-second response. Refer to Figure 3-2 below.
Note
At least one switch must be depressed,
but DO NOT energize more than one
switch at a time. It is recommended that
the system operate in the slowest mode
that is required by the system.
Positions 1, 2, and 3
Allow manual selection of range.
ZERO
RANGE
#2
RANGE
#3
RMT
O.T.
CH
RANGE
USE THUMBWHEEL
TO ADJUST
Figure 3-2. Front Panel Controls
1
2
3
CHECK
SWITCH
SPAN
TIME
CONSTANT
SWITCH
S9
5.0 SEC
2.5 SEC
1.0 SEC
0.5 SEC
Startup Rosemount Analytical Inc. A Division of Emerson Process Management
3-2
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