Teledyne 3000PA User Manual

Percent Oxygen Analyzer

OPERATING INSTRUCTIONS FOR

Model 3000PA

Percent Oxygen Anal yzer

DANGER

HIGHLY TOXIC AND OR FLAMMABLE LIQUIDS OR GASES MAY BE PRESENT IN THIS MONITORING SYSTEM.

PERSONAL PROTECTIVE EQUIPMENT MAY BE REQUIRED WHEN SERVICING THIS SYSTEM. HAZARDOUS VOLTAGES EXIST ON CERTAIN COMPONENTS INTERNALLY WHICH MAY PER-

SIST FOR A TIME EVEN AFTER THE POWER IS TURNED OFF AND DISCONNECTED. ONLY AUTHORIZED PERSONNEL SHOULD CONDUCT MAINTENANCE AND/OR SERVICING.

BEFORE CONDUCTING ANY MAINTENANCE OR SERVICING CONSULT WITH AUTHORIZED SUPERVISOR/MANAGER.

Teledyne Analytical Instruments

P/N M64573

08/06/99

ECO:#99-0323

Model 3000PA

All Rights Reserved. No part of this manual may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any other language or computer language in whole or in part, in any form or by any means, whether it be electronic, mechanical, magnetic, optical, manual, or otherwise, without the prior written consent of Teledyne Analytical Instruments, 16830 Chestnut Street, City of Industry, CA 91749-1580.

Warranty

This equipment is sold subject to the mutual agreement that it is warranted by us free from defects of material and of construction, and that our liability shall be limited to replacing or repairing at our factory (without charge, except for transportation), or at customer plant at our option, any material or construction in which defects become apparent within one year from the date of shipment, except in cases where quotations or acknowledgments provide for a shorter period. Components manufactured by others bear the warranty of their manufacturer. This warranty does not cover defects caused by wear, accident, misuse, neglect or repairs other than those performed by Teledyne or an authorized service center. We assume no liability for direct or indirect damages of any kind and the purchaser by the acceptance of the equipment will assume all liability for any damage which may result from its use or misuse.

We reserve the right to employ any suitable material in the manufacture of our apparatus, and to make any alterations in the dimensions, shape or weight of any parts, in so far as such alterations do not adversely affect our warranty.

Important Notice

This instrument provides measurement readings to its user, and serves as a tool by which valuable data can be gathered. The information provided by the instrument may assist the user in eliminating potential hazards caused by his process; however, it is essential that all personnel involved in the use of the instrument or its interface, with the process being measured, be properly trained in the process itself, as well as all instrumentation related to it.

The safety of personnel is ultimately the responsibility of those who control process conditions. While this instrument may be able to provide early warning of imminent danger, it has no control over process conditions, and it can be misused. In particular, any alarm or control systems installed must be tested and understood, both as to how they operate and as to how they can be defeated. Any safeguards required such as locks, labels, or redundancy, must be provided by the user or specifically requested of Teledyne at the time the order is placed.

Therefore, the purchaser must be aware of the hazardous process conditions. The purchaser is responsible for the training of personnel, for providing hazard warning methods and instrumentation per the appropriate standards, and for ensuring that hazard warning devices and instrumentation are maintained and operated properly.

Teledyne Analytical Instruments, the manufacturer of this instrument, cannot accept responsibility for conditions beyond its knowledge and control. No statement expressed or implied by this document or any information disseminated by the manufacturer or its agents, is to be construed as a warranty of adequate safety control under the

user’s process conditions.

Teledyne Analytical Instruments

Percent Oxygen Analyzer

Specific Model Information

The instrument for which this manual was supplied may incorporate one or more options not included with the standard instrument. Commonly available options are listed below, with check boxes. Any that are incorporated in the instrument for which this manual is supplied are indicated by a check mark in the box.

Instrument Serial Number _______________________

includes the following options:

! 3000PA-C: In addition to all standard features, this model also has

separate ports for zero and span gases, and built-in control valves. The internal valves are entirely under the control of the 3000PA electronics, to automatically switch between gases in synchronization with the analyzer’s operations

! 3000PA-S: In models with this option, all wetted parts are made

from 316 stainless steel.

! 3000PA-M: In models with this option, the 4-20 mA Analog Current

output is active. (In the standard units, it is not active.)

! 19" Rack Mnt: The 19" Relay Rack Mount units are available with

either one or two 3000 series analyzers installed on a 19" panel, and ready to mount in a standard rack.

! Cell Class: ___________________ See Maintenance for Specs.

Enter Class Designation.

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iii

Model 3000PA

1 Introduction

1.1 Overview........................................................................ 1-1

1.2 Typical Applications ....................................................... 1-1

1.3 Main Features of the Analyzer ....................................... 1-1

1.4 Model Designations....................................................... 1-2

1.5 Front P anel (Operator Interf ace) ..................................... 1-3

1.6 Recognizing Difference Between LCD & VFD............... 1-5

1.7 Rear Panel (Equipment Interface) .................................. 1-5

2 Operational Theory

2.1 Introduction .................................................................... 2-1

2.2 Micro-Fuel Cell Sensor .................................................. 2-1

2.2.1 Principles of Operation ............................................ 2-1

2.2.2 Anatomy of a Micro-Fuel Cell .................................. 2-2

2.2.3 Electrochemical Reactions...................................... 2-3

2.2.4 The Eff ect of Pressure.............................................. 2-4

2.2.5 Calibration Characteristics ...................................... 2-4

2.2.6 Micro-Fuel Cell “Class”............................................ 2-5

2.3 Sample System.............................................................. 2-6

2.4 Electronics and Signal Processing ................................ 2-8

Table of Contents

3 Installation

3.1 Unpacking the Analyzer................................................. 3-1

3.2 Mounting the Analyzer ................................................... 3-1

3.3 Rear Panel Connections................................................ 3-2

3.3.1 Gas Connections ................................................... 3-3

3.3.2 Electrical Connections........................................... 3-4

3.3.3 Remote Probe Connector ...................................... 3-9

3.4 Installing the Micro-Fuel Cell ......................................... 3-9

3.5 Testing the System.........................................................3-11

4 Operation

4.1 Introduction .................................................................... 4-1

4.2 Using the Data Entry and Function Buttons ................... 4-2

4.3 The

4.3.1 Setting the Display................................................. 4-4

4.3.2 Setting up an Auto-Cal........................................... 4-5

4.3.3 Password Protection.............................................. 4-5

System

4.3.3.1 Entering the Password................................... 4-6

Function ..................................................... 4-3

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Percent Oxygen Analyzer

4.3.3.2 Installing or Changing the Password ............. 4-7

4.3.4 Logout.................................................................... 4-8

4.3.5 System Self-Diagnostic Test .................................. 4-9

4.3.6 Version Screen ...................................................... 4-9

Zero

and

Span

4.4 The

4.4.1 Cell Failure ............................................................ 4-12

4.4.2 Span Cal................................................................ 4-11

4.4.2.1 Auto Mode Spanning ..................................... 4-11

4.4.2.2 Manual Mode Spanning................................. 4-12

4.5 The

4.6 The

4.6.1 Setting the Analog Output Ranges......................... 4-16

4.6.2 Autoranging Analysis............................................. 4-16

4.6.3 Fixed Range Analysis ............................................ 4-16

4.7 The

4.8 Signal Output ................................................................. 4-17

Alarms Range

Analyze

Function...................................................... 4-12

Function ...................................................... 4-15

Function.................................................... 4-17

Functions ....................................... 4-10

Maintenance

5.1 Routine Maintenance..................................................... 5-1

5.2 Cell Replacement .......................................................... 5-1

5.2.1 Storing and Handling Replacement Cells ............... 5-1

5.2.2 When to Replace a Cell........................................... 5-2

5.2.3 Removing the Micro-Fuel Cell ................................. 5-3

5.2.4 Installing a New Micro-Fuel Cell.............................. 5-5

5.2.5 Cell W arranty ........................................................... 5-5

5.3 Fuse Replacement ......................................................... 5-6

5.4 System Self Diagnostic Test........................................... 5-6

5.5 Major Internal Components............................................ 5-7

5.6 Cleaning ........................................................................ 5-8

5.7 Troubleshooting ............................................................. 5-9

Appendix

A-1 Model 3000PA Specifications ........................................ A-1

A-2 Recommended 2-Year Spare Parts List ......................... A-3

A-3 Drawing List................................................................... A-4

A-4 19-Inch Relay Rack Panel Mount................................... A-4

A-5 Application Notes on Restrictors, Pressures & Flow...... A-5

A-6 Zero Functions............................................................... A-8

Teledyne Analytical Instruments

Model 3000PA

DANGER

COMBUSTIBLE GAS USAGE WARNING

This is a general purpose instrument designed for usage in a nonhazardous area. It is the customer's responsibility to ensure safety especially when combustible gases are being analyzed since the potential of gas leaks always exist.

The customer should ensure that the principles of operating of this equipment is well understood by the user . Misuse of this product in an y manner , tampering with its components, or unauthorized substitution of any component may adversely affect the safety of this instrument.

Since the use of this instrument is beyond the control of T eledyne, no responsibility by T eled yne, its affiliates, and agents for damage or injury from misuse or neglect of this equipment is implied or assumed.

Teledyne Analytical Instruments

Percent Oxygen Analyzer Introduction 1

Introduction

1.1 Overview

The Teledyne Analytical Instruments Model 3000PA Percent Oxygen Analyzer is a versatile microprocessorbased instrument for detecting the percentage of oxygen in a variety of background gases. This manual covers the Model 3000PA General Purpose flush-panel and/or rack-mount units only. These units are for indoor use in a nonhazardous environment.

1.2 Typical Applications

A few typical applications of the Model 3000PA are:

• Monitoring inert gas blanketing

• Air separation and liquefaction

• Chemical reaction monitoring

• Semiconductor manufacturing

• Petrochemical process control

• Quality assurance

• Gas analysis certification.

1.3 Main Features of the Analyzer

The Model 3000PA Percent Oxygen Analyzer is sophisticated yet simple to use. The main features of the analyzer include:

• A 2-line alphanumeric display screen, driven by microprocessor electronics, that continuously prompts and informs the operator.

• High resolution, accurate readings of oxygen content from low percent levels through 100 %. Large, bright, meter readout.

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1 Introduction Model 3000PA

• Advanced Micro-Fuel Cell, designed for percent oxygen analysis. Several options are available.

• Versatile analysis over a wide range of applications.

• Microprocessor based electronics: 8-bit CMOS microprocessor

with 32 kB RAM and 128 kB ROM.

• Three user definable output ranges (from 0-1% through 0-100 %) allow best match to users process and equipment.

• Air-calibration range for convenient spanning at 20.9 %.

• Auto Ranging allows analyzer to automatically select the proper

preset range for a given measurement. Manual override allows the user to lock onto a specific range of interest.

• Two adjustable concentration alarms and a system failure alarm.

• Extensive self-diagnostic testing, at startup and on demand, with

continuous power-supply monitoring.

• Two way RFI protection.

• RS-232 serial digital port for use with a computer or other digital

communication device.

• Analog outputs for percent-of-range and for range identification. 0–1 V dc. (Isolated 4–20 mA dc optional)

• Convenient and versatile, steel, flush-panel or rack-mountable case with slide-out electronics drawer.

1.4 Model Designations

3000PA: Standard model. 3000PA-C: In addition to all standard features, this model also has

3000PA-M: This model has current output signals (4-20 mA) for percent-

of-range and range ID, in addition to voltage outputs.

3000PA-S: A Stainless Steel Probe and Probe Holder are used in this

model, for use where resistance to corrosion is important.

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Percent Oxygen Analyzer Introduction 1

All of the above options are available in combination. For example, the

-C and -V options are combined as Model 3000PA-C-V.

Figure 1-1: Model 3000PA Front Panel

1.5 Front Panel (Operator Interface)

The standard 3000PA is housed in a rugged metal case with all controls and displays accessible from the front panel. See Figure 1-1. The front panel has thirteen buttons for operating the analyzer, a digital meter, an alphanumeric display, and a window for viewing the sample flowmeter.

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1 Introduction Model 3000PA

Function Keys: Six touch-sensitive membrane switches are used to

change the specific function performed by the analyzer:

• Analyze Perform analysis for oxygen content of a sample gas.

• System Perform system-related tasks (described in detail in

chapter 4, Operation.).

• Span Span calibrate the analyzer.

• Zero Zero calibrate the analyzer.

• Alarms Set the alarm setpoints and attributes.

• Range Set up the 3 user definable ranges for the instrument.

Data Entry Keys: Six touch-sensitive membrane switches are used to

input data to the instrument via the alphanumeric VFD display:

• Left & Right Arrows Select between functions currently

displayed on theVFD screen.

• Up & Down Arrows Increment or decrement values of

functions currently displayed.

• Enter Moves VFD display on to the next screen in a series. If

none remains, returns to the

• Escape Moves VFD display back to the previous screen in a

series. If none remains, returns to the

Digital Meter Display: The meter display is a LED device that

produces large, bright, 7-segment numbers that are legible in any lighting environment. It produces a continuous readout from 0-100 %. It is accurate across all ranges without the discontinuity of analog range switching.

Alphanumeric Interface Screen: The VFD screen is an easy-to-use

interface from operator to analyzer. It displays values, options, and messages that give the operator immediate feedback.

Flowmeter: Monitors the flow of gas past the sensor. Readout is 0.2 to

2.4 standard liters per minute (SLPM).

Standby Button: The Standby turns off the display and outputs,

but circuitry is still operating.

Analyze

screen.

Analyze

screen.

CAUTION: The power cable must be unplugged to fully

disconnect power from the instrument. When chassis is exposed or when access door is open and power cable is connected, use extra care to avoid contact with live electrical circuits.

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Percent Oxygen Analyzer Introduction 1

Access Door: To provide access to the Micro-Fuel Cell, the front panel swings open when the latch in the upper right corner of the panel is pressed all the way in with a narrow gauge tool. Accessing the main circuit board requires unfastening the rear panel screws and sliding the unit out of the case.

1.6 Recognizing Difference Between LCD & VFD

LCD has GREEN background with BLACK characters. VFD has DARK background with GREEN characters. In the case of VFD - NO CONTRAST ADJUSTMENT IS NEEDED.

1.7 Rear Panel (Equipment Interface)

The rear panel, shown in Figure 1-2, contains the gas and electrical connectors for external inlets and outlets. The Zero and Span gas connectors, and the Current signal outputs are optional and may not appear on your instrument. The connectors are described briefly here and in detail in the Installation chapter of this manual.

Figure 1-2: Model 3000PA Rear Panel

• Power Connection Universal AC power source.

• Gas Inlet and Outlet One inlet (must be externally valved)

and one exhaust out.

• Analog Outputs 0-1 V dc concentration output, plus

0-1 V dc range ID.

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1 Introduction Model 3000PA

• Alarm Connections 2 concentration alarms and 1 system

alarm.

• RS-232 Port Serial digital concentration signal output

and control input.

• Remote Probe Used in the 3000PA for controlling

external solenoid valves only.

• Remote Span/Zero Digital inputs allow external control of

analyzer calibration. (See Note, below.)

• Calibration Contact To notify external equipment that

instrument is being calibrated and readings are not monitoring sample.

• Range ID Contacts Four separate, dedicated, range relay

contacts. Low, Medium, High, Cal.

• Network For future expansion. Not implemented

at this printing.

Optional:

• Calibration Gas Ports Separate fittings for zero, span and

sample gas input, and internal valves for automatically switching the gases.

• Current Signal Output Additional isolated 4-20 mA dc plus

4-20 mA dc range ID.

Note: If you require highly accurate Auto-Cal timing, use external

Auto-Cal control where possible. The internal clock in the Model 3000PA is accurate to 2-3 %. Accordingly, internally scheduled calibrations can vary 2-3 % per day.

1-6

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Percent Oxygen Analyzer Operational Theory 2

Operational Theory

2.1 Introduction

The analyzer is composed of three subsystems:

1. Micro-Fuel Cell Sensor

2. Sample System

3. Electronic Signal Processing, Display and Control

The sample system is designed to accept the sample gas and transport it through the analyzer without contaminating or altering the sample prior to analysis. The Micro-Fuel Cell is an electrochemical galvanic device that translates the amount of oxygen present in the sample into an electrical current. The electronic signal processing, display and control subsystem simplifies operation of the analyzer and accurately processes the sampled data. The microprocessor controls all signal processing, input/output and display functions for the analyzer.

2.2 Micro-Fuel Cell Sensor

2.2.1 Principles of Operation

The oxygen sensor used in the Model 3000P series is a Micro-Fuel Cell designed and manufactured by Analytical Instruments. It is a sealed plastic disposable electrochemical transducer.

The active components of the Micro-Fuel Cell are a cathode, an anode, and the 15% aqueous KOH electrolyte in which they are immersed. The cell converts the energy from a chemical reaction into an electrical current in an external electrical circuit. Its action is similar to that of a battery.

There is, however, an important difference in the operation of a battery as compared to the Micro-Fuel Cell: In the battery, all reactants are stored within the cell, whereas in the Micro-Fuel Cell, one of the reactants (oxygen) comes from outside the device as a constituent of the sample gas being

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2 Operational Theory Model 3000PA

analyzed. The Micro-Fuel Cell is therefore a hybrid between a battery and a true fuel cell. (All of the reactants are stored externally in a true fuel cell.)

2.2.2 Anatomy of a Micro-Fuel Cell

The Micro-Fuel Cell is a cylinder only 1¼ inches in diameter and 1 inch thick. It is made of extremely inert plastic, which can be placed confidently in practically any environment or sample stream. It is effectively sealed, although one end is permeable to oxygen in the sample gas. The other end of the cell is a contact plate consisting of two concentric foil rings. The rings mate with spring-loaded contacts in the sensor block assembly and provide the electrical connection to the rest of the analyzer. Figure 2-1 illustrates the external features.

Figure 2-1: Micro-Fuel Cell

Refer to Figure 2-2, Cross Section of a Micro-Fuel Cell, which illustrates the following internal description.

Figure 2-2. Cross Section of a Micro-Fuel Cell (not to scale)

At the top end of the cell is a diffusion membrane of Teflon, whose thickness is very accurately controlled. Beneath the diffusion membrane lies

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Percent Oxygen Analyzer Operational Theory 2

the oxygen sensing element—the cathode—with a surface area almost 4 cm2. The cathode has many perforations to ensure sufficient wetting of the upper surface with electrolyte, and it is plated with an inert metal.

The anode structure is below the cathode. It is made of lead and has a proprietary design which is meant to maximize the amount of metal available for chemical reaction.

At the rear of the cell, just below the anode structure, is a flexible membrane designed to accommodate the internal volume changes that occur throughout the life of the cell. This flexibility assures that the sensing membrane remains in its proper position, keeping the electrical output constant.

The entire space between the diffusion membrane, above the cathode, and the flexible rear membrane, beneath the anode, is filled with electrolyte. Cathode and anode are submerged in this common pool. They each have a conductor connecting them to one of the external contact rings on the contact plate, which is on the bottom of the cell.

2.2.3 Electrochemical Reactions

The sample gas diffuses through the Teflon membrane. Any oxygen in the sample gas is reduced on the surface of the cathode by the following HALF REACTION:

O2 + 2H2O + 4e

––

–

––

→ 4OH

––

–

––

(cathode)

(Four electrons combine with one oxygen molecule—in the presence of water from the electrolyte—to produce four hydroxyl ions.)

When the oxygen is reduced at the cathode, lead is simultaneously oxidized at the anode by the following HALF REACTION:

Pb + 2OH

––

–

––

→ Pb+2 + H2O + 2e

––

–

––

(anode)

(Two electrons are transferred for each atom of lead that is oxidized. Therefore it takes two of the above anode reactions to balance one cathode reaction and transfer four electrons.)

The electrons released at the surface of the anode flow to the cathode surface when an external electrical path is provided. The current is proportional to the amount of oxygen reaching the cathode. It is measured and used to determine the oxygen concentration in the gas mixture.

The overall reaction for the fuel cell is the SUM of the half reactions above, or:

2Pb + O2 → 2PbO

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2 Operational Theory Model 3000PA

(These reactions will hold as long as no gaseous components capable of oxidizing lead—such as iodine, bromine, chlorine and fluorine—are present in the sample.)

The output of the fuel cell is limited by (1) the amount of oxygen in the cell at the time and (2) the amount of stored anode material.

In the absence of oxygen, no current is generated.

2.2.4 The Effect of Pressure

In order to state the amount of oxygen present in the sample as a percentage of the gas mixture, it is necessary that the sample diffuse into the cell under constant pressure.

If the total pressure increases, the rate that oxygen reaches the cathode through the diffusing membrane will also increase. The electron transfer, and therefore the external current, will increase, even though the oxygen concentration of the sample has not changed. It is therefore important that the sample pressure at the fuel cell (usually vent pressure) remain constant between calibrations.

2.2.5 Calibration Characteristics

Given that the total pressure of the sample gas at the surface of the Micro-Fuel Cell input is constant, a convenient characteristic of the cell is that the current produced in an external circuit is directly proportional to the rate at which oxygen molecules reach the cathode, and this rate is directly proportional to the concentration of oxygen in the gaseous mixture. In other words it has a linear characteristic curve, as shown in Figure 2-3. Measuring circuits do not have to compensate for nonlinearities.

In addition, since there is zero output in the absence oxygen, the characteristic curve has close to an absolute zero. In the percent ranges, the cell itself does not need to be zeroed. In practical application zeroing is still used to compensate for zero offsets in the electronics. (The electronics is zeroed automatically when the instrument power is turned on.)

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Percent Oxygen Analyzer Operational Theory 2

Figure 2-3. Characteristic Input/Output Curve for a Micro-Fuel Cell

2.2.6 Micro-Fuel Cell “Class”

TBE manufactures Micro-Fuel Cells with a variety of characteristics to give the best possible performance for any given sample conditions. A few typical Micro-Fuel Cells are listed below with their typical use and electrical specifications.

2.2.6.1 Class A-3 Cell

The class A-3 cell is for use in applications where it is exposed continuously to carbon dioxide concentrations between 1 % and 100 % in the sample gas.

Nominal output in air is 0.20 mA, and 90 % response time is 45 s. Expected life in flue gas is 8 months.

2.2.6.2 Class A-5 Cell

The class A-5 cell is for use in applications where it is exposed intermittently to carbon dioxide concentrations up to 100 % in the sample gas.

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2 Operational Theory Model 3000PA

Nominal output in air is 0.19 mA, and 90 % response time is 45 s.

Expected life in flue gas is 8 months.

2.2.6.3 Class B-1 Cell

The class B-1 cell is for use in applications where it is exposed to less

than 0.1 % of carbon dioxide, and where fast response is important.

Nominal output in air is 0.50 mA, and 90 % response time is 7 s.

Expected life in air is 8 months.

2.2.6.4 Class B-3 Cell

The class B-3 cell is for use in applications where a slightly longer

response time is acceptable in order to have a longer cell life.

Nominal output in air is 0.30 mA, and 90 % response time is 13 s.

Expected life in air is 12 months.

2.2.6.5 Class C-3 Cell

The class B-1 cell is for use in applications where it is exposed to less than 0.1 % of carbon dioxide, and where a longer response time is acceptable in order to have a longer cell life.

Nominal output in air is 0.20 mA, and 90 % response time is 30 s. Expected life in air is 18 months.

2.2.6.6 Hydrogen and/or Helium Service

If the sample gas contains 10 % or more hydrogen and/or helium, “clamp” cells are used. These Micro-Fuel cells are identified by the suffix -C added to the cell class number.

2.3 Sample System

The sample system delivers gases to the Micro-Fuel Cell sensor from the analyzer rear panel inlet. Depending on the mode of operation either sample or calibration gas is delivered.

The Model 3000P sample system is designed and fabricated to ensure that the oxygen concentration of the gas is not altered as it travels through the sample system. The sample encounters almost no dead space. This mini-

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Percent Oxygen Analyzer Operational Theory 2

mizes residual gas pockets that can interfere with very low level oxygen analysis.

The sample system for the standard instrument incorporates ¼ inch tube fittings for sample inlet and outlet connections at the rear panel. For metric system installations, 6 mm adapters are supplied with each instrument. The sample or calibration gas flow through the system is monitored by a flowmeter downstream from the cell. Figure 2-4 shows the piping layout for the standard model.

Figure 2-4: Piping Layout and Flow Diagram for Standard Model

Figure 2-5 is the flow diagram for the sampling system. In the standard instrument, calibration gases (zero and span) can be connected directly to the Sample In port by teeing to the port with appropriate valves. The shaded portion of the diagram shows the components added when the –C option is ordered. The valving is installed inside the 3000PA-C enclosure and is regulated by the instrument's internal electronics.

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2 Operational Theory Model 3000PA

Span I n

Zero In

Sample In

In vacuum service the restrictor should be placed here .

In normal service the restrictor should be placed here .

Solenoid Valves

Components in the shaded area are in the -C option (inter nal control valves) only and are not shown in the piping diagram above.

Cell

Exhaust Ou t

Restrictor

Figure 2-5: Flow Diagram

2.4 Electronics and Signal Processing

The Model 3000P Percent Oxygen Analyzer uses an 8031 microcontroller with 32 kB of RAM and 128 kB of ROM to control all signal processing, input/output, and display functions for the analyzer. System power is supplied from a universal power supply module designed to be compatible with any international power source. Figure 2-6 shows the location of the power supply and the main electronic PC boards.

Flowmeter

2-8

Figure 2-6: Location of Electronic Components

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Percent Oxygen Analyzer Operational Theory 2

The signal processing electronics including the microprocessor, analog to digital, and digital to analog converters are located on the motherboard at the bottom of the case. The preamplifier board is mounted on top of the motherboard as shown in the figure. These boards are accessible after removing the back panel. Figure 2-7 is a block diagram of the Analyzer electronics.

Figure 2-7: Block Diagram of the Model 3000P Electronics

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+ 48 hidden pages

Teledyne 3000PA User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual