Rosemount AOTF-NIR Analyzer-Rev 1.2 Owner's manual

Brand: Rosemount

Model: AOTF-NIR Analyzer-Rev 1.2

Type: Owner's manual

AOTF-NIR™ ANALYZER

Instruction Bulletin IB-103-810 Rev. 1.2

IB-103-810

HIGHLIGHTS OF CHANGES

Effective May, 1995 Rev. 1

PAGE SUMMARY

1-3

5-13

General. In text and figures throughout manual, replaced "MLA 8100" nomenclature to reflect new

AOTF-NIR™ designation.

Figure 1-2. Added illustration of item 6, AOTF-NIR Communication Software Package.

Section 5-8.b. Deleted paragraph referencing software/firmware specification sheet.

Effective October, 1995 Rev. 1.1

PAGE SUMMARY

2-1 Removed explosion-proof classification from light source module.

Effective February, 1997 Rev. 1.2

PAGE SUMMARY

1-1

1-4

3-1

3-2

3-3

4-1

4-2

4-6

4-7

4-8

4-9

General update to reflect new software version 1.04.

Insert safety page.

Modify warranty page.

Change process liquid to process sample.

Change equipment specifications.

Update analyzer drawing.

Replace analog card description.

Add instructions to read safety page, replace in-situ probe drawing.

Add lifting instructions.

Update analyzer drawing.

Update Figure 4-9.

Update analyzer drawing.

IB-103-810

HIGHLIGHTS OF CHANGES (continued)

Effective February, 1997 Rev. 1.2

PAGE SUMMARY

4-10

6-1

7-1

8-1

8-2

8-4

9-1

Insert protective covers and safety ground warning.

Modify analyzer drawing.

Add fuse specifications.

IB-103-810

ROSEMOUNT WARRANTY

Rosemount warrants that the equipment manufactured and sold by it will, upon shipment, be free of

defects in workmanship or material. Should any failure to conform to this warranty become apparent during

a period of one year after the date of shipment, Rosemount shall, upon prompt written notice from the

purchaser, correct such nonconformity by repair or replacement, F.O.B. factory of the defective part or parts.

Correction in the manner provided above shall constitute a fulfillment of all liabilities of Rosemount with

respect to the quality of the equipment.

THE FOREGOING WARRANTY IS EXCLUSIVE AND IN LIEU OF ALL OTHER

WARRANTIES OF QUALITY WHETHER WRITTEN, ORAL, OR IMPLIED (INCLUDING

ANY WARRANTY OF MERCHANTABILITY OF FITNESS FOR PURPOSE).

The remedy(ies) provided above shall be purchaser's sole remedy(ies) for any failure of Rosemount to

comply with the warranty provisions, whether claims by the purchaser are based in contract or in tort

(including negligence).

Rosemount does not warrant equipment against normal deterioration due to environment. Factors such

as corrosive gases and solid particulates can be detrimental and can create the need for repair or replacement

as part of normal wear and tear during the warranty period.

Equipment supplied by Rosemount Analytical Inc., but not manufactured by it, will be subject to the same

warranty as is extended to Rosemount by the original manufacturer.

©ROSEMOUNT ANALYTICAL INC., 1993

COVERED BY U.S. PATENT # 0000000

OTHER FOREIGN PATENTS PENDING

IB-103-810

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.

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.

NOTE TO USERS

The number in the lower right corner of each illustration in this publication is a manual illustration

number. It is not a part number and is not related to the illustration in any technical manner.

PURPOSE

The purpose of this manual is to provide a comprehensive understanding of the AOTF-NIR Analyzer,

components, functions, installation, and maintenance.

This manual is designed to provide information about the AOTF-NIR. We recommend that you

thoroughly familiarize yourself with the Overview and Installation sections before installing your analyzer.

The overview presents the basic principles of the AOTF-NIR analyzer along with it's performance

characteristics and components. The remaining sections contain detailed procedures and information necessary

for installation and servicing of the AOTF-NIR.

Before contacting Rosemount concerning any questions, first consult this manual. It describes most

situations encountered in your equipment's operation and details necessary action.

DEFINITIONS

The following definitions apply to WARNINGS, CAUTIONS, and NOTES found throughout this

publication.

IB-103-810

iii

TABLE OF CONTENTS

Section Page

Rosemount Warranty .......................................................................... i

Purpose ..................................................................................... ii

I. SYSTEM OVERVIEW ............................................................... 1-1

1-1. Scope of Manual ................................................................. 1-1

1-2. Functional Equipment Description ................................................... 1-1

1-3. Components Checklist (Package Contents) ............................................ 1-3

1-4. Equipment Specifications .......................................................... 1-4

II. LIGHT SOURCE MODULE .......................................................... 2-1

2-1. Description ..................................................................... 2-1

2-2. Light Source and Transfer Optics ................................................... 2-1

2-3. Power Supply ................................................................... 2-1

III. ANALYZER MODULE ............................................................... 3-1

3-1. General Description .............................................................. 3-1

3-2. RF Amplifier ................................................................... 3-1

3-3. Optical Assembly ................................................................ 3-1

3-4. Electronics Package (Card Rack) .................................................... 3-2

3-5. General User Interface (GUI) ....................................................... 3-4

3-6. High Voltage Power Supply (HVPS) PCB ............................................ 3-5

3-7. Low Voltage Power Supply ........................................................ 3-5

3-8. Power Distribution and Output Termination Board ...................................... 3-5

IV. INSTALLATION .................................................................... 4-1

4-1. Overview of Installation ........................................................... 4-1

4-2. Mechanical Installation ........................................................... 4-1

4-3. Electrical Installation ............................................................. 4-5

4-4. Auxiliary Equipment Interface Connections ........................................... 4-7

4-5. Installation Inspection ............................................................ 4-10

V. OPERATION ........................................................................ 5-1

5-1. Overview ...................................................................... 5-1

Part 1 - Analyzer Operation with General User Interface ....................................... 5-1

5-2. Front Panel Controls and Indicators .................................................. 5-1

5-3. GUI Display and Operating Conventions ............................................. 5-2

5-4. Front Panel Menu Structure ........................................................ 5-2

5-5. Data Menu ..................................................................... 5-5

5-6. Calibrate Menu .................................................................. 5-6

5-7. Setup Menu .................................................................... 5-9

Part 2 - Analyzer Operation with a Personal Computer ........................................ 5-13

5-8. Hardware/Software Interface Requirements ........................................... 5-13

5-9. Software Usage Conventions ....................................................... 5-13

5-10. Software Program Startup ......................................................... 5-14

5-11. Communications Software Menu Structure ............................................ 5-15

5-12. Calibrate AOTF ................................................................. 5-17

5-13. Setup AOTF .................................................................... 5-27

5-14. Monitor Status .................................................................. 5-35

5-15. Services ....................................................................... 5-38

5-16. Quit .......................................................................... 5-41

IB-103-810

TABLE OF CONTENTS

Section Page

VI. TROUBLESHOOTING ............................................................... 6-1

6-1. General ........................................................................ 6-1

6-2. Alarm Messages ................................................................. 6-1

6-3. Troubleshooting ................................................................. 6-1

VII. PREVENTIVE MAINTENANCE ...................................................... 7-1

7-1. General ........................................................................ 7-1

7-2. Cleaning ....................................................................... 7-1

7-3. Checking Source Lamp Intensity .................................................... 7-1

VIII. SERVICE .......................................................................... 8-1

8-1. General ........................................................................ 8-1

8-2. Analyzer Components Replacement ................................................. 8-1

8-3. Light Source Module Components Replacement ........................................ 8-3

IX. REPLACEMENT PARTS ............................................................. 9-1

X. RETURNING EQUIPMENT TO THE FACTORY ...................................... 10-1

Appendix A. PLS OPERATION AND OPTIMIZING TECHNIQUES ............................ A-1

INDEX ..................................................................................... I-1

IB-103-810

LIST OF ILLUSTRATIONS

Figure Page

1-1. Functional Equipment Diagram ...................................................... 1-2

1-2. Typical AOTF-NIR System Package .................................................. 1-3

2-1. Light Source Module Components .................................................... 2-1

2-2. Light Source and Transfer Optics Diagram ............................................. 2-1

3-1. Analyzer Module Components ....................................................... 3-1

3-2. Analyzer Module Card Rack ......................................................... 3-2

3-3. Analog Output Board .............................................................. 3-3

3-4. Analog Board Reversible Dip Shunts (U17, U18, U4, U8) ................................. 3-4

3-5. General User Interface Features ...................................................... 3-4

4-1. In-Situ Transmission Probe .......................................................... 4-1

4-2. Optic Flow-Thru Coupler ........................................................... 4-2

4-3. Light Source Module Installation Drawing .............................................. 4-3

4-4. Analyzer Module Installation Drawing ................................................. 4-4

4-5. Cable Pull Box ................................................................... 4-4

4-6. Cable to Pull Tape Connection ....................................................... 4-5

4-7. Input Voltage Selector Switches, Analyzer Module ....................................... 4-6

4-8. Input Voltage Selector Switch, Light Source Module ..................................... 4-7

4-9. Conduit Port Locations ............................................................. 4-7

4-10. Input Power Terminal Blocks ........................................................ 4-8

4-11. Analog Output and Alarm Relay Terminals ............................................. 4-9

4-12. RS232 Interface Connector .......................................................... 4-9

4-13. Front Panel Main Menu Display ...................................................... 4-10

5-1. AOTF-NIR Front Panel ............................................................ 5-1

5-2. Sample HELP Display ............................................................. 5-2

5-3. GUI Menu Structure Version 1.04 .................................................... 5-3

5-4. Typical DATA Menu Display ........................................................ 5-5

5-5. CONC Option Display Format ....................................................... 5-5

5-6. Typical TEMP Display ............................................................. 5-5

5-7. Typical DIAG Display ............................................................. 5-6

5-8. CALIBRATE Menu Display ........................................................ 5-6

5-9. SAMPLE DATA Display ........................................................... 5-7

5-10. CDATA Display .................................................................. 5-8

5-11. SCALE Display ................................................................... 5-8

5-12. Typical SETUP Display ............................................................ 5-9

5-13. Typical ALARM Relay Setup Display ................................................. 5-10

5-14. Typical ANALOG OUT Setup Display ................................................ 5-11

5-15. AOTF-NIR Communications Software - Opening Screen .................................. 5-14

5-16. Main Menu Display ............................................................... 5-15

5-17. AOTF-NIR Communications Software Menu Structure ................................... 5-16

5-18. Calibrate AOTF Menu ............................................................. 5-17

5-19. Scan Table Menu .................................................................. 5-18

5-20. Create Scan Window ............................................................... 5-19

5-21. DOS File Name Entry Window ...................................................... 5-20

5-22. Typical DOS Directory/File Name Display ............................................. 5-21

5-23. Reference Scan Menu .............................................................. 5-22

5-24. Typical DOS Directory/File Name Display ............................................. 5-23

5-25. Typical Trigger Scan Window ....................................................... 5-24

5-26. Scan Graph Source Window ......................................................... 5-25

5-27. Typical Scan Graph ................................................................ 5-26

5-28. Setup AOTF Menu ................................................................ 5-27

5-29. Typical Calibration Files Window .................................................... 5-28

IB-103-810

LIST OF ILLUSTRATIONS (Continued)

Figure Page

5-30. Typical Scan Files Window ......................................................... 5-29

5-31. Typical Front Panel Display Setup Window ............................................. 5-30

5-32. Typical Calibration Scale Setup Window ............................................... 5-31

5-33. Typical Analog Output Setup Window ................................................. 5-32

5-34. Typical Alarm Setup Window ....................................................... 5-33

5-35. Typical AOTF Configuration Files Window ............................................ 5-34

5-36. Monitor Status Menu .............................................................. 5-35

5-37. Typical Monitor AOTF Status Printout ................................................ 5-36

5-38. Typical AOTF Monitor Display ...................................................... 5-37

5-39. Services Menu .................................................................... 5-38

5-40. Typical PC Setup Window .......................................................... 5-39

6-1. AOTF-NIR Troubleshooting Flowchart #1 ............................................. 6-2

6-2. AOTF-NIR Troubleshooting Flowchart #2 ............................................. 6-3

8-1. GUI and LED Assemblies, Exploded View ............................................. 8-1

8-2. Analyzer Module Fuses and POWER ON/OFF Switch .................................... 8-2

8-3. Source Lamp Assembly, Exploded View ............................................... 8-3

8-4. Light Source Module Fuses and POWER ON/OFF Switch ................................. 8-4

LIST OF TABLES

Table Page

1-1 AOTF-NIR Equipment Specifications ................................................. 1-4

5-1. Sample Data Variables and Options ................................................... 5-7

5-2. Calculate Setup Variables and Options ................................................. 5-8

5-3. Concentration Scaling Variables and Options ........................................... 5-9

5-4. Alarm Setup Variables and Options ................................................... 5-11

5-5. Analog Output Setup Variables and Options ............................................ 5-12

5-6. Scan Table Variables/Settings ........................................................ 5-19

5-7. Analog Output Variables/Settings ..................................................... 5-32

5-8. Alarm Setup Variables/Settings ...................................................... 5-33

5-9. Monitor Status Printout Description ................................................... 5-36

5-10. PC Setup Variables/Settings ......................................................... 5-40

9-1. Replacement Parts for the AOTF-NIR Analyzer ......................................... 9-1

IB-103-810

1-1

SECTION I. SYSTEM OVERVIEW

1-1. SCOPE OF MANUAL. This instruction bulletin

covers installation, setup, operation, troubleshooting,

and maintenance of the AOTF-NIR™ Analyzer,

manufactured by Rosemount Analytical, Incorporated.

The troubleshooting and service procedures in this

manual are limited to those that can be performed by

most equipment operators.

1-2. FUNCTIONAL EQUIPMENT DESCRIPTION

When properly configured, the AOTF-NIR Analyzer

can detect and measure the concentration of sample

components that absorb light in the near-infrared

spectrum.

Functional components of the analyzer (Figure 1-1)

include a light source, an optical sampling chamber

(sample cell), an acousto-optic absorption filter and

detector (optics pedestal) and a microprocessor. The

light source is housed in a source module, while the

optics pedestal, microprocessor and related electronics

are housed in an analyzer module. In normal use, an

output flow from the sample process being monitored

is routed through the sample cell.

a. Light Source and Sample Cell

. The light source

sends a beam of light through a condensing lens

and a fiber optic cable to the sample cell. On the

input side of the sample cell, a collimating lens

aligns the light beam to project parallel rays across

the cell. As process sample flows through the

sample cell, the collimated light rays pass through

the sample.

Depending on the chemical content of the process

sample, specific wavelengths of near-infrared light

are absorbed. For absorbed wavelengths, high

concentrations of light-absorbing components

greatly reduce the number (intensity) of light rays

passing through the sample. Smaller

concentrations of the same components absorb

fewer rays of light in the absorbed wavelengths.

Unabsorbed light passes through the sample and

strikes a second condensing lens. This lens focuses

the light onto another fiber optic cable. This cable

transmits the beam to the optics pedestal.

b. Optics Pedestal. At the optics pedestal, the

condensed light passes through another collimator

lens. This lens projects the light's rays onto the

face of an Acousto-Optic Tunable Filter (AOTF).

The AOTF is an adjustable light filter. The filter

includes an acoustic transducer bonded to a

Tellurium Dioxide (TeO

) crystal.

The acoustic transducer is driven by high energy

acoustic frequencies from an RF amplifier. The

transducer generates shock waves of the same

frequency as the input signal. These shock waves

cause the TeO

crystal to expand and contract. As

the TeO

crystal expands and contracts, its spectral

grating (light filtering capability) changes.

Therefore, by controlling the output of the RF

amplifier, the AOTF-NIR Analyzer tunes the

AOTF to pass discrete wavelengths of light.

For each scan of the process sample, the analyzer

sends a series of different frequencies to the AOTF

crystal. Each frequency allows a different

bandwidth of light to pass. The analyzer identifies

the bandwidth of the passing light by the acoustic

frequency that allows it to pass. The importance of

this will be seen later.

The rays of light passing through the AOTF

crystal are collected by a condensing lens. The

condensing lens focuses the rays onto a

photodiode detector. Due to a piezo-electric effect,

the incident light causes the detector to generate an

electrical (millivolt) output. The amplitude of the

output signal is directly related to the intensity of

the light striking the detector. These millivolt

output signals are then amplified and sent to the

analyzer's microprocessor.

c. Signal Processing and Conditioning Circuits

Signals to and from the optics pedestal are

processed and conditioned in the detector pre-amp,

DSP, and RF Synthesizer Modulator, and

Amplifier circuits. These circuits are described in

Section III of this manual.

d. Microprocessor

. The microprocessor records the

light intensity (absorption) data received from the

photodiode detector. The light intensity data is

stored as a function of the acoustic frequency in

the AOTF assembly. By substituting wave

numbers for their related acoustic frequencies, the

microprocessor develops an absorption pattern

(frequency vs. intensity) for the sample process

components.

IB-103-810

1-2

DETECTOR

PRE-AMP

AMPLIFIER

TEMPERATURE

CONTROL

PHOTODIODE

DETECTOR

AOTF

SIGNAL

PROCESSING

AND

CONDITIONING

CIRCUITS

OPTICS PEDESTAL

TEMPERATURE

CONTROL

SAMPLE

CHAMBER

SAMPLE CELL

COLLIMATING

LENS

CONDENSING

LENS

FIBER OPTIC

CABLE

FIBER OPTIC CABLE

ANALYZER MODULE

LIGHT SOURCE

CONDENSING

LENS

DSP

MODULATOR

SYNTHESIZER

ANALOG

OUTPUTS

MICRO-

PROCESSOR

TO USER’S

ALARM/RECORDING

EQUIPMENT

18300028

RS232

BIDIRECTIONAL

INTERFACE CONNECTOR

Figure 1-1. Functional Equipment Diagram

IB-103-810

1-3

2254001

AOTF-NIR

Next, the microprocessor compares the scanned

absorption pattern with standard patterns that were

recorded under controlled conditions. By matching

specific absorption patterns, the microprocessor

identifies the particular components present in the

sample.

The microprocessor also compares the intensities

of passing light with recorded baseline values and

uses the resulting ratios to define the percentage of

each component in solution.

The components identification and concentration

data is sent to the front panel LCD display.

Depending on the setup at your installation, the

resulting data can also be sent to chart recorders,

CRT displays, and/or electronic storage. By using

the AOTF-NIR Analyzer to set process control

limits, the components concentration data can also

be used to trigger alarms or solenoid valves in the

host system.

1-3. COMPONENTS CHECKLIST (PACKAGE

CONTENTS). A typical Rosemount AOTF-NIR

Process Analyzer system should contain the items

shown in Figure 1-2.

ITEM

DESCRIPTION

Analyzer Module

Sample Cell

Light Source Module

Fiber Optic Cables

Instruction Bulletin

AOTF-NIR Communication

Software

Figure 1-2. Typical AOTF-NIR System Package

IB-103-810

1-4

1-4. EQUIPMENT SPECIFICATIONS.

Table 1-1. AOTF-NIR Equipment Specifications.

Operating Modes: Scanning Mode, Analyzer Mode

Spectral Range: 1.1 to 2.2 microns

Spectral Resolution: 50 cm

-1

Wavelength Repeatability: 0.04 cm

-1

Stray Light: 1% or less

Photometric Noise: Less than 50 micro absorbance units

Scan Speed: Spectral Element: 5 to 400 ms

Scan: 5.2 to 26 seconds for 255 spectral elements

Typical Error: Less than 1% of full scale, application dependent

Data Displays: 4 line, 20 characters per line LCD, user's PC/CRT

Operating Temperature: Analyzer Module: 0° to 45°C

Light Source Module: 0° to 45°C

Storage Temperature: 32° to 122°F (0° to +50°C)

Relative Humidity: 20% to 99% non-condensing

Warm Up Time: 60 minutes

Data Protection: Lithium Battery (5 year life)

Input Power: 115 or 230 Vac, 50 or 60 Hz

Power Rating: Analyzer: 100 VA

Light Source: 50 VA

Electrical Classification: Category II

Source Life: 1 year

Environmental Classification: NEMA-4 (IP 55)

Dimensions:

(H x W x D)

Analyzer Module: 20 x 20 x 13.4 in.

(508 x 508 x 340 mm)

Light Source Module: 11.8 x 7.9 x 5.12 in.

(300 x 201 x 130 mm)

Weight: Analyzer Module: 60 lbs (27.2 kg)

Light Source Module: 15 lbs (6.8 kg)

Certification: CE Mark

IB-103-810

2-1/2-2

(ENCLOSURE COVER

NOT SHOWN)

18300027

ITEM

DESCRIPTION

Quartz Halogen

Lamp

Transfer Optics

Power Supply

Enclosure

SMA Connector

ITEM

DESCRIPTION

Fuse Holders

POWER

ON/OFF

Switch

Input Power

Connector

QUARTZ

HALOGEN

LAMP

LENS

ASSEMBLY

FIBER OPTIC

CABLE

18300029

SECTION II. LIGHT SOURCE MODULE

2-1. DESCRIPTION. The source module (Figure 2-1)

contains a quartz halogen lamp, transfer optics, and

power supply in a NEMA-4 enclosure. A female SMA

connector on the side of the enclosure is provided for

connecting a fiber optic cable.

Figure 2-1. Light Source Module Components

Figure 2-2. Light Source and Transfer

Optics Diagram

2-2. LIGHT SOURCE AND TRANSFER OPTICS

. The

quartz halogen lamp (Figure 2-2) produces an intense,

but dispersed light beam with energy bandwidths in the

near-infrared spectrum. The transfer optics (lens

assembly) collects the dispersed light and focuses an

intense beam onto the end of the fiber optic cable. The

fiber optic cable transports the light energy intact along

the full length of the cable.

2-3. POWER SUPPLY

. The lamp power supply operates

on 120 or 240 Vac, 50 or 60 Hz power source. The

power supply provides 5.0 volts dc to the quartz

halogen lamp. An ON/OFF switch and two fuse

holders are located on the face of the power supply

(Figure 2-1).

A 3-pole input power connector is located below the

power supply cover for connection of a plant power

source. Refer to Section IV for switch selections, fuse

requirements, and electrical hookup.

IB-103-810

3-1

2254000

AOTF-NIR

SECTION III. ANALYZER MODULE

3-1. GENERAL DESCRIPTION. The analyzer module

(Figure 3-1) contains three main components: the RF

amplifier, the optical assembly, and the electronics

package. In addition, the analyzer module includes a

General User Interface (GUI), high voltage power

supply, low voltage power supply, power distribution

and output termination board, and cooling fan. Except

for the cooling fan, each of these components is

described in the following paragraphs.

3-2. RF AMPLIFIER

. The RF amplifier receives a

series of frequency signals from the electronics

package. The amplifier increases the amplitude of the

frequency signals and sends them to the Acousto-Optic

Tunable Filter (AOTF) on the optical assembly.

3-3. OPTICAL ASSEMBLY

. The optical assembly

includes a collimator assembly, an acousto-optic

tunable filter, and a convex condensing lens. During

normal operation, the collimator receives light from the

source cell via a fiber optic cable.

a. Collimator Assembly

. Incoming light is emitted

from the fiber optic cable in a dispersed pattern.

The collimator collects and aligns the light and

projects parallel light rays onto the AOTF crystal.

ITEM

DESCRIPTION

RF Amplifier

Optics Pedestal

Electronics Package

General User Interface

High Voltage Power Supply

Low Voltage Power Supply

Power Distribution Board

Cooling Fan

Hinge Pin

Figure 3-1. Analyzer Module Components

IB-103-810

3-2

22540012

ITEM

DESCRIPTION

Frequency

Synthesizer

Card

DSP Card

CPU Card

ITEM

DESCRIPTION

EEPROM

Memory Card

Analog Output

Card

I/O Card

Backplane

b. Acousto-Optic Tunable Filter (AOTF)

. The

AOTF assembly is made up of an acoustic (piezo-

electric) transducer and a tunable filter made of

Tellurium Dioxide (TeO

) crystal. The AOTF

assembly controls the passage of discrete

wavelengths of near-infrared light to pass through

a spectral grating (optical filter).

By changing the frequency received from the RF

amplifier, the spectral grating of the filter is

adjusted. At any given acoustic frequency, the

filter will pass a discrete wavelength of light. The

analyzer sends a series of different frequencies to

the AOTF crystal in order to scan all discrete

wavelengths within a specified bandwidth.

c. Condensing Lens

. The light passing through the

AOTF crystal is collected by a convex condensing

lens. The condensing lens causes the light to

converge and focus on the PbS detector assembly.

This allows the full intensity of the passing light to

be detected and measured.

d. PbS Detector Assembly

. The PbS detector

assembly includes a lead sulfide (PbS) photodiode

detector and a preamplifier board. Both are

mounted on top of the optical assembly.

The photodiode detector converts light energy into

electrical energy. When a condensed beam of light

strikes the photodiode, the photodiode emits a

small voltage. The voltage level of the signal is

directly related to the intensity (energy) of the light

beam. The electrical signal (millivolts) is sent

directly to the preamplifier. The preamplifier

conditions the electrical signal for processing in

the electronics package.

3-4. ELECTRONICS PACKAGE (CARD RACK)

. The

electronics package (card rack) (Figure 3-2) contains

six printed circuit boards connected to a nine card

backplane.

The printed circuit boards used in the card rack

include: the frequency synthesizer card, the Digital

Signal Processing (DSP) card, the microprocessor

(CPU) card, the memory card, the analog output card,

and the Input/Output (I/O) card. The function of each

card is described in the following paragraphs.

Figure 3-2. Analyzer Module Card Rack

a. Frequency Synthesizer Card

. The frequency

synthesizer card generates RF signals at specific

frequencies and amplitudes. The frequencies and

amplitudes of the RF signals are controlled by the

analyzer's microprocessor. The microprocessor is

programmed to output specific RF scan signals.

The program is generated by the operator using a

scan configuration (calibration) routine.

b. Digital Signal Processing (DSP) Card

. The DSP

card analyses the intensities of analog electrical

signals being received from the PbS detector

circuits. Based on these analyses, it produces

digital measurement data for use in the analyzer's

microprocessor.

IB-103-810

3-3

The DSP card also sends amplitude modulation

signals to the frequency synthesizer card. These

signals are used to amplify or attenuate the power

of RF signals generated in the frequency

synthesizer card. The amplitude modulation

signals control signal levels in the RF amplifier,

AOTF, and PbS detector circuits. By modulating

these signals, the analyzer can better interpret the

intensity signals being received from the PbS

detector circuits.

c. Microprocessor (CPU) Card

. The micro-

processor card contains EEPROM for long term

storage of analyzed data, Random Access Memory

(RAM) for storage of temporary data, and a

programmed EEPROM for storage of the analyzer

control program.

Through the control program, the microprocessor

helps generate control signals in the analyzer

circuits. The microprocessor also helps process

and quantify analog signals generated in the

analyzer circuits.

In addition, the microprocessor processes signals

to and from EEPROM and RAM for parallel

communications with the GUI and serial

communications with the RS232 port.

d. Memory Card

. The memory card is interfaced

with the microprocessor card to provide additional

data storage space in the analyzer.

e. Analog Output Boards

. By itself, the analog

output board, Figure 3-3, has two independent

output channels. The first channel (Output 1) is

user configured to represent either instantaneous

opacity, transmittance, optical density, extinction,

or dust density. The second channel (Output 2)

can send instantaneous or average values.

The EPA now requires a third analog output

channel. The additional channel is to confirm the

optical pathlength correction ratio (OPLR)

correction. To establish the third channel, a piggy-

back board, Figure 3-3, can be added to the analog

output board. The additional board provides two

additional analog output channels. One channel is

to meet the EPA requirement. The second channel

can be used as an auxiliary output of instantaneous

or average values of opacity, transmittance, optical

density, extinction, dust density, or transceiver

temperature.

Figure 3-3. Analog Output Board

IB-103-810

3-4

22540018

AOTF-NIR

ITEM

DESCRIPTION

DATA Key

CAL Key

SETUP Key

ENTER Key

▲ Key

▼ Key

ESC Key

HELP Key

ITEM

DESCRIPTION

Liquid Crystal

Display

POWER Indicator

RUN Indicator

PLS Indicator

ALARM

Indicator

Parameter Access

Key

The four analog channels can be set for either

voltage or current operation. Figure 3-4 shows dip

shunt locations and orientations. In the voltage

mode the output is 0-10 Vdc. In the current mode

the outputs can be configured from the SETUP

menu to either a 0-20 mA or 4-20 mA range. Both

output types have short circuit protection.

To change from current to voltage output (or from

voltage to current) the configuration of reversible

dip shunts must be changed. The reversible shunt

is removed, rotated 180°, and replaced in the

socket.

Figure 3-4. Analog Board Reversible Dip Shunts

(U17, U18, U4, U8)

f. Input/Output (I/O) Card

. The I/O card receives

inputs and controls output to an AOTF crystal

heater and a PbS detector cooler. With circuitry on

the high-voltage power supply board and sensing

and heating elements in the AOTF assembly, the

I/O card helps to control the temperature of the

TeO

crystal.

With circuitry on the PbS preamplifier board and

sensing and cooling elements located near the PbS

detector, the I/O card also helps to control the

temperature of the PbS crystal.

The I/O card also provides driver signals to an

optocoupler located on the PbS preamplifier board.

The optocoupler controls alarm relays on the

power distribution and output termination board.

3-5. GENERAL USER INTERFACE (GUI)

. The GUI

(Figure 3-5) is used to examine process components

data and equipment operating parameters. These types

of information are accessible by the use of the DATA

key.

Figure 3-5. General User Interface Features

IB-103-810

3-5/3-6

The GUI can also be used to change the equipment

configuration for analysis of different process

components. It may also be used to change alarm and

error report levels or select alternate devices for data

output. Equipment configuration tasks are performed

using the CAL (calibration) and SETUP keys.

NOTE

Equipment configuration and programming

operations are most easily performed at the

user's personal computer (PC).

The ENTER, ▲, ▼ and ESC keys are used to scroll

through program menus, make menu selections, or exit

a menu. A HELP key is provided for display of

information about selected menu options, etc.

The GUI has a 4-line, 20-character per line Liquid

Crystal Display (LCD) for message and data display.

The LCD is backlighted for low light conditions. A

potentiometer is provided on the back of the GUI for

changing the viewing angle of the display.

POWER, RUN, PLS, and ALARM indicators (LEDs)

light up to indicate the operating status of the AOTF-

NIR Analyzer. Refer to Section V, Part 1 for GUI

operating procedures.

3-6. HIGH VOLTAGE POWER SUPPLY (HVPS)

PCB. The high voltage power supply provides a 30

Vdc bias voltage to the detector circuit. The bias

voltage helps amplify light intensity signals coming

from the PbS detector.

The HVPS also provides from 0 to 3 Vdc to the AOTF

crystal heater element. The exact voltage depends on

an analog output from a temperature sensor in the

AOTF assembly. The output of the sensor is sent to the

I/O card. The I/O card converts the signal from analog

to digital and sends it on to the analyzer's computer.

The computer responds with a heater control signal to

the HVPS. In turn, the HVPS delivers more or less

voltage to the heater element.

3-7. LOW VOLTAGE POWER SUPPLY

. The low

voltage power supply provides +5 Vdc, +12 Vdc,

-12 Vdc, and +28 Vdc voltages for use in the

electronics circuits.

3-8. POWER DISTRIBUTION AND OUTPUT

TERMINATION BOARD. The power distribution

and output termination board interfaces the analyzer

with the user's power source, alarms, and process

control devices.

Incoming (115/130 Vac) power is routed through four

separate circuits. Separate fuses are provided for each

leg of the 115/230 Vac power distribution circuit.

All alarm relay and analog output terminals are also

located on the power distribution and output

termination board. This allows the user to easily locate

and interface alarms, indicators, valves, and/or chart

recorders with the analyzer.

IB-103-810

4-1

Before starting to install this equipment

read the “Safety instructions for the

wiring and installation of this apparatus”

at the front of this Instruction Bulletin.

Failure to follow the safety instructions

could result in serious injury or death.

The fiber optic cables must be handled

carefully. Avoid bending, pulling, or

compressing the cables. Excessive

mechanical stress on the fiber optic cable

or its connectors can cause permanent

cable damage.

The in-situ transmission probe is a

delicate precision optics devise. Careless

handling or installation can result in

permanent damage to the probe.

Male fiber optic cable terminals are

protected by plastic caps. Keep these

terminals covered whenever the fiber

optic cables are disconnected. Save the

plastic caps and use them whenever

storing or transporting the equipment.

The in-situ transmission probe is a

delicate precision optics device. Careless

handling or installation can result in

permanent damage to the probe.

51.6mm

311.1mm

25.4mm

Gap Width

56.4mm

45°

Probe Body

Fiber Optic

Connector

SECTION IV. INSTALLATION

4-1. OVERVIEW OF INSTALLATION. This section

covers installation of the Rosemount AOTF-NIR

Analyzer. Observe the following cautions when

handling the analyzer equipment.

4-2. MECHANICAL INSTALLATION

. The AOTF-

NIR Analyzer system includes an analyzer module and

a light source module. These two modules are housed

in separate NEMA-4 cabinets designed for wall

mounting. The NEMA-4 cabinets are suitable for use

in a Class I, Division II Environment when equipped

with an ISA Type Z Purge.

The analyzer system also includes an Optic In-Situ

Transmission Probe designed for mounting in a process

tank, or an Optic Flow-Thru Coupler designed for

mounting in-line with the process plumbing. The

transmission probe and flow-thru coupler are generally

referred to as source cells throughout this manual. The

type of source cell provided with a particular analyzer

system is customer-dependent.

Two fiber optic cables are provided for signal

transmission between the light source module, source

cell, and analyzer module. One cable connects the light

source module to the source cell. The second cable

connects the source cell to the analyzer module. Refer

to the following paragraphs for detailed source cell

installation procedures.

a. In-Situ Transmission Probe Setup and

Installation. If your analyzer system is equipped

with an In-Situ Transmission Probe (Figure 4-1),

install the probe according to the following

instructions:

1. The path length of the in-situ transmission

probe is adjustable. Refer to Figure 4-1. Use

spanner wrench provided to loosen body and

reflector locking rings; turn locking rings

counterclockwise to loosen.

2. Unscrew reflector from sleeve and sleeve from

probe body to adjust gap width between lens

faces. Adjust to approximately one half the

desired path length. When properly adjusted,

the gap width should be centered in oblong slot

in sleeve.

3. With approximate gap width set, use spanner

wrench to snug up one of the two locking

rings. Do not overtighten locking ring.

Figure 4-1. In-Situ Transmission Probe

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Rosemount AOTF-NIR Analyzer-Rev 1.2 Owner's manual

Rosemount AOTF-NIR Analyzer-Rev 1.2 Owner's manual

Rosemount AOTF-NIR Analyzer-Rev 1.2 Owner's manual

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