Rosemount 868 NDIR Analyzer-Rev N Owner's manual

Brand: Rosemount

Model: 868 NDIR Analyzer-Rev N

Type: Owner's manual

Instruction Manual

748003-N

November 2002

http://www.processanalytic.com

Model 868

Non-Dispersive Infrared Analyzer

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: [email protected]

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

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 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.

• 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.

Instruction Manual

748003-N

November 2002

Rosemount Analytical Inc. A Division of Emerson Process Management Contents i

Model 868

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

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November 2002

ii Contents Rosemount Analytical Inc. A Division of Emerson Process Management

Model 868

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

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

Instruction Manual

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November 2002

Rosemount Analytical Inc. A Division of Emerson Process Management Contents iii

Model 868

LIST OF ILLUSTRATIONS

Figure 2-1.

Line Voltage Selection ........................................................................................... 2-2

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

When Sensitivity of Range 2 is 100/60 Times Sensitivity of Range 1................. 7-12

Figure 7-7. Example Showing Relationship Between Range 2 and Range 1 Responses

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

Instruction Manual

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November 2002

iv Contents Rosemount Analytical Inc. A Division of Emerson Process Management

Model 868

DRAWINGS

(LOCATED IN REAR OF MANUAL)

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

Instruction Manual

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November 2002

Rosemount Analytical Inc. A Division of Emerson Process Management Preface P-1

Model 868

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.

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.

Instruction Manual

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November 2002

P-2 Preface Rosemount Analytical Inc. A Division of Emerson Process Management

Model 868

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 IN-

STRUCTIONS.

DANGER.

ELECTRICAL SHOCK HAZARD

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.

Instruction Manual

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November 2002

Rosemount Analytical Inc. A Division of Emerson Process Management Preface P-3

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

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.

Instruction Manual

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November 2002

P-4 Preface Rosemount Analytical Inc. A Division of Emerson Process Management

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

F (52

C). A flame should

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.

Instruction Manual

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November 2002

Rosemount Analytical Inc. A Division of Emerson Process Management Preface P-5

Model 868

DOCUMENTATION

The following Model 868 instruction materials are available. Contact Customer Service Center or the local

representative to order.

748003 Instruction Manual (this document)

Instruction Manual

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November 2002

P-6 Preface Rosemount Analytical Inc. A Division of Emerson Process Management

Model 868

CONDENSED STARTUP AND CALIBRATION PROCEDURE

Prior to shipment, this analyzer was subjected

to extensive factory performance testing, during

which all necessary optical and electrical ad-

justments were made. The following instruc-

tions are recommended for initial startup and

subsequent standardization of the analyzer. In

most cases, these simple instructions are suffi-

cient to operate the analyzer. The detailed in-

structions 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 pres-

sure 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-

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 re-

quired. Any leakage must be cor-

rected before introduction of sample

and/or application of electrical power.

Power Verification

1. Verify power switch settings are cor-

rect 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.

SWITCH

POSITION

FUNCTION READING

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 V

7 - Source V

8 Source I

9 Preamp Out

Table P-1. Range Switch Settings

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.

Determined by application. See Infrared Analyzer Calibration and Data Sheet, located in the rear of this manual.

Instruction Manual

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November 2002

Rosemount Analytical Inc. A Division of Emerson Process Management Preface P-7

Model 868

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 con-

trol 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 de-

sired 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 de-

sired reading. (S7 is the least sensitive

switch).

Time Constant Switch S9

Set switch S9 to the desired speed of re-

sponse of the electronics (time constant).

The analyzer is now calibrated for all three

ranges and is ready for sample analysis.

Instruction Manual

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November 2002

Preface Rosemount Analytical Inc. A Division of Emerson Process Management

P-8

Model 868

Instruction Manual

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November 2002

Rosemount Analytical Inc. A Division of Emerson Process Management Description and Specifications 1-1

Model 868

SECTION 1

DESCRIPTION AND SPECIFICATIONS

1-1 OVERVIEW

The Model 868 Non-Dispersive Infrared Ana-

lyzer (NDIR) continuously determines the con-

centration of a particular component of interest

in a flowing mixture. The analysis is based on a

differential measurement of the absorption of in-

frared energy. With the proper selection of de-

tector, optics and cells, the instrument has a

wide range of applications, subject only to the

limitation that the analysis involve the determi-

nation of a single component, which must ab-

sorb 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

two cells. This difference is a measure of

the concentration of the component of inter-

est 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 potenti-

ometric (voltage) recorder is provided as

standard. Additional outputs (0 to 10 mV, 0

to 100 mV, 0 to 1 VDC) are available as op-

tions.

A calibration curve may be used to convert

display or recorder readings into concentra-

tion values. The analyzer may utilize an op-

tional linearizer circuit for linear readout of

concentration values on the display and on

a recorder.

The analyzer is equipped for remote selec-

tion of ranges.

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November 2002

Description and Specifications Rosemount Analytical Inc. A Division of Emerson Process Management

1-2

Model 868

1-2 SPECIFICATIONS

Repeatability.................................. 1% of fullscale

Noise ............................................. 1% of fullscale

Zero/Span Drift

............................. ±1% of fullscale per 24 hours

Response Time (Electronic).......... Variable, 90% of fullscale in 0.5 to 5 seconds, field selectable

Sensitivity ...................................... 500 p/10

fullscale carbon monoxide 200 p/10

fullscale carbon

dioxide

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

19 inches (483 mm) W

16 inches (406 mm) D (with handles)

Weight ........................................... 32 lbs (15 kg)

Shipping Weight ............................ Approximately 46 pounds (21 kg)

Performance specifications based on an ambient temperature variation of less than 20°F (11°C) per hour.

Instruction Manual

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November 2002

Rosemount Analytical Inc. A Division of Emerson Process Management Installation 2-1

Model 868

SECTION 2

INSTALLATION

2-1 UNPACKING

Carefully examine the shipping carton and con-

tents 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 vibra-

tion.

The analyzer must be installed in a weather-

protected, 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 varia-

tions:

• 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 prop-

erly grounded 3-wire source of electrical

supply.

CAUTION

Before applying power, perform the Volt-

age Select procedure below.

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).

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Installation Rosemount Analytical Inc. A Division of Emerson Process Management

2-2

Model 868

Figure 2-1. Line Voltage Selection

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).

Figure 2-2. Heater Voltage Select

c. Fuse Select Panel

The fuse select panel is located on the rear

panel. Select the appropriate amperage:

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)

• Input impedance greater than 5K ohms

2-7 REMOTE RANGE

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 5-

3f on page 5-6.

2-8 SAMPLE INLET/OUTPUT CONNECTIONS

Sample inlet and outlet connections are lo-

cated on the rear panel. This instrument is

intended for atmospheric pressure opera-

tion only. Vent must go to atmosphere.

Connections are ¼ inch tubing.

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 re-

corder 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 speci-

fied, use dry nitrogen for the zero gas.

110

–

115 VAC

115

–

130 VAC

207-230 VAC

230-254 VAC

115V

230V

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November 2002

Rosemount Analytical Inc. A Division of Emerson Process Management Installation 2-3

Model 868

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 incorpo-

rates such components as pumps, valves to

permit selection of sample, zero standard, or

upscale standard gas; needle valve in sample-

inlet line for flow adjustment; flowmeter for flow

measurement and/or indication of flow stop-

page; 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.

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 in-

dicator 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 indi-

cates leaks.

5. Correct any leakage for introduction of

sample and/or application of electrical

power.

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 at-

mospheric sampling pressure, i.e., the out-

let 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 at-

mosphere, 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.).

At 7.5 to 8.0 CFH (3.8 to 4 L/min.), there-

fore, the pressure is increased by about 1%,

and the output signal is thereby increased

by about the same 1% over static condi-

tions. 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 pres-

sure, 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 tem-

peratures are equilibrated to instrument

temperature regardless of stream tempera-

ture. At extremely high flow rates, this may

not be true, but no such effect has been

noted up to 18 CFH (9 L/min.).

Instruction Manual

748003-N

November 2002

Installation Rosemount Analytical Inc. A Division of Emerson Process Management

2-4

Model 868

Cell Length

mm inch

Cell Volume (CC)

(Without inlet tube)

Total Volume (CC)

(Cell with inlet tube)

Time For Two Volumes @ 2

Scfh (1L/min)

@ 750 mm Hg

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

Table 2-1. Purging Time at Atmospheric Sample Pressure

2-13 DIFFERENTIAL ANALYSIS WITH FLOW

THROUGH REFERENCE CELL

In some applications the analyzer is used to

measure the difference between the concentra-

tion of the component of interest in two sample

streams. If so, the reference side of the ana-

lyzer, as well as the sample side, utilizes a flow-

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 con-

taining the lower concentrations of this

component.

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Rosemount 868 NDIR Analyzer-Rev N Owner's manual

Rosemount 868 NDIR Analyzer-Rev N Owner's manual

Rosemount 868 NDIR Analyzer-Rev N Owner's manual

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