GE Sensing CGA 351 Operating Manual

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Measurement & Control Oxygen Analysis

CGA 351

Zirconium Oxide Oxygen Analyzer

User’s Manual

910-199 Rev. E

May 2013

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CGA 351

Zirconium Oxide Oxygen Analyzer

User’s Manual

910-199 Rev. E May 2013

ge-mcs.com

Technical content subject to change without notice.

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[no content intended for this page]

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Preface

Information Paragraphs

Note paragraphs provide information that provides a deeper understanding of the situation, but is not essential to

•

the proper completion of the instructions.

• Important paragraphs provide information that emphasizes instructions that are essential to proper setup of the

equipment. Failure to follow these instructions carefully may cause unreliable performance.

• Caution! paragraphs provide information that alerts the operator to a hazardous situation that can cause damage to

property or equipment.

• Warning! paragraphs provide information that alerts the operator to a hazardous situation that can cause injury to

personnel. Cautionary information is also included, when applicable.

Safety Issues

WARNING! It is the responsibility of the user to make sure all local, county, state and national codes,

regulations, rules and laws related to safety and safe operating conditions are met for each installation.

Auxiliary Equipment

Local Safety Standards

The user must make sure that he operates all auxiliary equipment in accordance with local codes, standards, regulations, or laws applicable to safety.

Working Area

WARNING! Auxiliary equipment may have both manual and automatic modes of operation. As equipment

can move suddenly and without warning, do not enter the work cell of this equipment during automatic operation, and do not enter the work envelope of this equipment during manual operation. If you do, serious injury can result.

WARNING! Make sure that power to the auxiliary equipment is turned OFF and locked out before you

perform maintenance procedures on the equipment.

Qualification of Personnel

Make sure that all personnel have manufacturer-approved training applicable to the auxiliary equipment.

Personal Safety Equipment

Make sure that operators and maintenance personnel have all safety equipment applicable to the auxiliary equipment. Examples include safety glasses, protective headgear, safety shoes, etc.

Unauthorized Operation

Make sure that unauthorized personnel cannot gain access to the operation of the equipment.

CGA 351 User’s Manual iii

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Preface

Environmental Compliance

Waste Electrical and Electronic Equipment (WEEE) Directive

GE Measurement & Control Solutions is an active participant in Europe’s Waste Electrical and Electronic Equipment (WEEE) take-back initiative, directive 2002/96/EC.

The equipment that you bought has required the extraction and use of natural resources for its production. It may contain hazardous substances that could impact health and the environment.

In order to avoid the dissemination of those substances in our environment and to diminish the pressure on the natural resources, we encourage you to use the appropriate take-back systems. Those systems will reuse or recycle most of the materials of your end life equipment in a sound way.

The crossed-out wheeled bin symbol invites you to use those systems.

If you need more information on the collection, reuse and recycling systems, please contact your local or regional waste administration.

Visit http://www.ge-mcs.com/en/about-us/environmental-health-and-safety/1741-weee-req.html take-back instructions and more information about this initiative.

for

iv CGA 351 User’s Manual

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Contents

Chapter 1. General Information

1.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

1.2 The Sensor Enclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

1.3 The Sample System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

1.4 Principles of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.5 The Zirconium Oxide Oxygen Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

1.6 The Heater Control Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Chapter 2. Installation

2.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

2.2 Choosing an Installation Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

2.3 Mounting the CGA 351. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

2.4 Connecting the Sample System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

2.5 Wiring the Analyzer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

2.5.1 Wiring the Outputs (TB1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

2.5.2 Wiring the Inputs (TB2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

2.5.3 Wiring the Line Power (TB3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Chapter 3. Operation

3.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

3.2 Preventing Common Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

3.3 Powering Up the System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

3.4 User Program Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

3.5 Configuring the Digital Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

3.5.1 Initial Screen Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

3.5.2 Configuration Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

3.5.3 Using the Auto Range Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

3.5.4 Configuring the Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

3.5.5 Configuring the Analog Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

3.5.6 Switching Display Windows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

3.6 Converting mV to Oxygen Concentration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

3.7 Powering Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

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Contents

Chapter 4. Setup and Calibration

4.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

4.2 Accessing the User Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

4.3 The [Cal] Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

4.4 Setting Up the Alarm Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

4.4.1 Setting the Trip Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

4.4.2 Setting the Trip Value. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

4.4.3 Setting the Deadband Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

4.4.4 Testing the Alarm Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

4.4.5 Selecting the Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

4.5 Setting the Temperature Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

4.5.1 Entering the Setpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

4.5.2 Entering the Sensor Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

4.5.3 Setting the Air Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

4.5.4 Selecting the Gas Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

4.5.5 Selecting the Proportional Band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

4.5.6 Setting the Integration Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

4.5.7 Setting the Maximum Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

4.5.8 Restoring the Default Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

4.6 Auto Range Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

4.6.1 Factory Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

4.6.2 Programming the Auto Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

4.7 The [Opt-User] Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46

4.8 Setting Fault Alarm Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

4.9 Setting Up the Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

4.9.1 Selecting the Analog Output Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49

4.9.2 Setting the Zero Setpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50

4.9.3 Setting the Span Setpoint. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

4.9.4 Testing the Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

4.9.5 Setting the Zero Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

4.9.6 Setting the Span Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

4.10 Adjusting the Display Contrast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

4.11 Setting the Display Backlight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

4.12 Setting Up the Serial Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

4.12.1 Entering the Node ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

4.12.2 Entering the Baud Rate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

4.12.3 Entering the Number of Data Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

4.12.4 Entering the Parity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

4.12.5 Entering the Number of Stop Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

4.12.6 Selecting the Type of Serial Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

4.13 Setup and Security Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

4.13.1 Setting Up the Option Card Slots. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

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4.13.2 Setting the Security Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

4.14 Calibrating the CGA 351 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

4.14.1 Recommended Calibration Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

4.14.2 Regulating the Calibration Gas Flow Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

4.14.3 Adjusting the Calibration Setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

4.15 Checking the Current Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

4.15.1 Checking the Sensor Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

4.15.2 Viewing the Heater Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

Chapter 5. Service and Maintenance

5.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

5.2 General Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

5.2.1 Checking the Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

5.2.2 Checking the Thermocouple . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

5.2.3 Checking the Oxygen Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

5.2.4 Checking the Sensor Furnace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

5.2.5 Checking the Sensor Furnace Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

5.3 Oxygen Measurement Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

5.3.1 Oxygen Concentration Reads Constant 20.93%. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

5.3.2 Oxygen Reading Above 100%. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76

5.3.3 Oxygen Reading Too Low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76

5.3.4 Oxygen Reading Too High . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76

5.4 Calibration Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

5.4.1 Everything Is Fine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

5.4.2 Forced Flow Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

5.4.3 Plugging or Dead Space Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

5.5 Parts Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

5.5.1 The Sensor Enclosure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79

5.5.2 The Electronics Enclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

5.6 Recommended Spare Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87

Chapter 6. Specifications

6.1 General Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91

6.2 Operating Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92

6.3 Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93

Appendix A. The Nernst Equation

A.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95

A.2 Equilibrium Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95

A.3 The CGA 351 Nernst Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96

CGA 351 User’s Manual vii

Page 10

Contents

Appendix B. CE Mark Compliance

B.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

B.2 EMC Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99

B.3 LVD Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Appendix C. Optional Enclosures

C.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

C.2 Rack Mount Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

C.2.1 Mounting the Rack Mount CGA 351 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

C.2.2 Connecting the Sample System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

C.2.3 Wiring the Rack Mount CGA 351 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

C.3 Rack Mount Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

C.4 Rack Mount Service and Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

C.4.1 Parts Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

C.4.2 Replacing the Fuses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

viii CGA 351 User’s Manual

Page 11

Chapter 1. General Information

1.1 Introduction

The CGA 351 monitors the oxygen content of any clean and dry gas stream. The analyzer can accurately measure oxygen levels from 0.1 ppm to 100% O

accomplished with a precision, temperature-controlled, zirconium oxide (zirconia) oxygen sensor.

The standard CGA 351 analyzer, as shown in Figure 1 below , is supplied in a pair of stainless steel enclosures mounted side-by-side on a metal plate with a 40” flexible conduit connecting the two. This compact, wall-mounted system includes the following components:

• A sensor enclosure, which contains the oxygen sensor, sensor furnace, thermocouple, inlet port with needle

valve, outlet port with flowmeter, and interconnecting cable(s), and

• An electronics enclosure, which contains the temperature control circuitry, output signal processing circuitry,

digital display, user interface, and wiring terminal strips.

The CGA 351 analyzer is also available in optional enclosures (see Appendix C for more information).

, and can even measure oxygen content in reducing gases. This is

Figure 1: Standard CGA 351 Analyzer

CGA 351 User’s Manual 1

Page 12

Chapter 1. General Information

Furnace Bracket

Flowmeter

Thermocouple

Needle Valve

Sensor Furnace

Oxygen Sensor

Manifold

Electrical Conduit

1.2 The Sensor Enclosure

The sensor enclosure, which is shown in Figure 4 below, houses the sample measurement components. The functions of these components are as follows:

• A zirconium oxide (zirconia) oxygen sensor converts the oxygen concentration of the sample gas into a mV

output signal.

• A sensor furnace heats the oxygen sensor and the sample gas to the optimum temperature of 700°C.

• A thermocouple precisely regulates the temperature of the oxygen sensor and the sample gas.

• An inlet needle valve and an outlet flowmeter adjust the sample gas flow to 400 ± 40 cc/min.

2 CGA 351 User’s Manual

Figure 2: Sensor Enclosure

Page 13

Chapter 1. General Information

SAMPLE

INLET

SAMPLE OUTLET

INLET

CAL-GAS

INPUTOUTPUT

To: CGA 351 Inlet

From: CGA 351 Outlet

1.3 The Sample System

In addition to the components supplied with the CGA 351, an external sample system may be required to ensure that the analyzer is fed a properly conditioned sample or calibration gas stream. In particular, the gas must be clean and dry, and it must be delivered to the analyzer at atmospheric pressure.

Note: A suitable sample system, which will be supplied completely assembled on its own mounting plate, may be

ordered directly from GE. Commonly used sample system components include filters, pressure regulators, pressur e gauges, by-pass loops, and sample pumps. It is recommended that stainless steel construction be used for all wetted parts of the sample system. A typical sample system is shown in Figure 3 below.

Figure 3: Typical Sample System

CGA 351 User’s Manual 3

Page 14

Chapter 1. General Information

1.4 Principles of Operation

A gas sample is drawn into the inlet port of the analyzer by gas diffusion and a forced flow determined by the external sample system. The sample gas then flows through a ceramic inlet tube and into the annular space between the inlet tube and the inside of the zirconium oxide oxygen sensor. The flowmeter on the outlet port and the needle valv e on the inlet port are used to adjust the sample flow rate to 400 ± 40 cc/min.

In the annular sample space, the gas is heated to the same 700°C at which the zirconium oxide oxygen sensor is maintained. A mV signal is generated. This signal is proportional to the logarithm of the ratio of the oxygen concentration in the sample gas to the oxygen concentration in a reference gas contacting the outer electrode. In the display electronics, the logarithmic signal can be read directly in unlinearized form, or it can be converted to a 0/4–20 mA, 0–2 V, or Namur linearized signal before display.

Note: A temperature above 650°C is required for proper operation of the oxygen sensor. Also, ambient air is the

usual reference gas on the outside of the zirconium oxide sensor.

The sensor furnace also generates the convective flow that circulates the sample gas through the sample path. Pushed from behind by the hot gases still in the furnace, the hot sample gas in the sensor furnace rises out of the furnace and cools. The cooled sample gases then pass through the outlet port, where they are carried away by the main gas flow.

A platinum coating on the end of the ceramic tube and the zirconium oxide oxygen sensor ensures that all oxidation/reduction reactions in the sample gas reach equilibrium. It is therefore possible to measure such parameters as excess oxygen in air/fuel mixtures and equilibrium oxygen in reducing atmospheres such as hydrogen.

4 CGA 351 User’s Manual

Page 15

Chapter 1. General Information

Volts

Sample O

Inside Cell

Oxygen ions migrate through the zirconium oxide along the concentration gradient.

From Outside

Electrode

From Inside Electrode

Zirconium Oxide Ceramic with Lattice Imperfections

Atmospheric O

Outside Cell

When O concentration in sample gas falls, the cell voltage rises

with increased oxygen migration through the zirconium oxide.

1.5 The Zirconium Oxide Oxygen Sensor

The inside and outside of the zirconium oxide oxygen sensor are coat ed wit h porou s plat inum, forming two electrodes. The sample gas flows past the inside of the sensor, while atmospheric air circulates freely on the outside of the sensor. This atmospheric air is used as the reference gas for making oxygen measurements (see Figure 4 below).

At the operating temperature of the oxygen sensor, the atmospheric reference oxygen is electrochemically reduced at

Figure 4: Oxygen Migration in the Zirconium Oxide Sensor

the outer electrode, and the resulting oxygen ions seek to equalize with the lower oxygen concentration on the sample side of the cell by migrating through the porous ceramic toward the inner electrode. At the inner electrode they give up electrons to become oxygen molecules again, and are swept away by the sample flow.

The lower the concentration of oxygen in the sample gas, the greater the rate of ion migration through the ceramic, and the higher the cell voltage due to electron exchange at the electrodes. The cell voltage rises logarithmically as the amount of oxygen in the sample gas falls, allowing the accurate measurement of very low levels of excess oxygen.

CGA 351 User’s Manual 5

Page 16

Chapter 1. General Information

1.6 The Heater Control Circuit

The oxygen sensor temperature in the CGA 351 is maintained by a heater, which is part of a complex temperature control loop. This circuit constantly monitors the temperature input from an RTD, compares it to the set point temperature, and turns the heater ON or OFF accordingly. The specific type of control circuit, a Proportional Integral Derivative (PID) loop, is used because of the adjustable parameters involved:

• Proportional Band: Because the system cannot respond instantaneously to temperature changes, the actual

temperature of the oxygen sensor oscillates about the set point. In general, increasing the proportional band reduces the magnitude of these temperature oscillations.

• Integral Action: A consequence of increasing the proportional band is the introduction of an offset between

the set point and the control point. The integral portion of the control loop acts to move the control point back toward the set point within a specified period of time. Decreasing this integration time reduces the offset more quickly.

Note: A third parameter, Derivative Action, is not used with the CGA 351.

The heater control circuit is configured at the factory for optimum performance. Because of the strong interaction between the parameters involved, properly setting up the PID loop is a very complex matter. As a result, randomly changing the P or I parameters can seriously degrade the performance of the CGA 351.

IMPORTANT: Always contact GE before attempting to change the default P or I values. The submenu for performing

these changes is password protected to prevent accidental changes.

6 CGA 351 User’s Manual

Page 17

Chapter 2. Installation

2.1 Introduction

This chapter provides a general description of the standard CGA 351 and gives directions on how to install and wire the analyzer for proper operation.

Note: For information regarding component locations and/or wiring connections in an optional enclosure, see

Appendix C.

IMPORTANT: For compliance with the European Union’s Low Voltage Directive (2006/95/EC), the CGA 351 requires

an external power disconnect device such as a switch or circuit breaker. The disconnect device must be marked as such, clearly visible, directly accessible, and located within 1.8 m (6 ft) of the unit.

WARNING! Power up the CGA 351 as quickly as possible after introduction of the sample gas. If the analyzer

is left installed without power, the unit’s components become susceptible to acid condensation that will cause corrosion.

Be sure to observe all installation limits and precautions described in this chapter. Pay particular attention to the ambient temperature range of –25 to +50°C (–13 to +122°F) specified for the instrument.

WARNING! To ensure safe operation of the CGA 351, the unit must be installed and operated as described in

this manual. Also, be sure to follow all applicable local safety codes and regulations for installing electrical equipment. In addition, all procedures should be performed by trained service personnel.

2.2 Choosing an Installation Site

All environmental and installation factors should have been discussed with a GE application engineer or field sales person at the time the CGA 351 was ordered. Thus, the equipment should be suited to the application and the planned installation site. Before installing the unit, however , read the following guidelines to verify that the best installation site has been chosen for optimum instrument accuracy and reliability. Make sure that:

• The CGA 351 enclosures are suitable for the environmental conditions at the installation site.

• The analyzer system will be installed in a location with little or no vibration.

• The ambient temperature at the installation site is between –25° and 50°C (–13° and 122 °F ) .

• There are no restrictions in the discharge line (i.e. flow control valves downstream of the meter).

• The CGA 351 system is installed in a location that provides ready access for programming, testing, and

servicing the unit.

• The cables will be protected from excessive physical strain (bending, pulling, twisting, etc.). Do not subject the

cables to temperatures above 65°C (149°F) or below –50°C (–58°F).

• The line voltage used at the planned installation site corresponds to the factory preset line voltage rating for the

meter.

CGA 351 User’s Manual 7

Page 18

Chapter 2. Installation

2.3 Mounting the CGA 351

This section explains how to mount the analyzer components at the installation site and how to connect the sample system to the analyzer.

Note: If more than one analyzer system is being installed, be aware that each system is a matched set (i.e., each

sensor enclosure must enclosures to match the systems correctly.

IMPORTANT: For compliance with the European Union’s Low Voltage Directive (2006/95 /EC), th e CGA 351 requires

IMPORTANT: This symbol indicates Caution - risk of electric shock:

Refer to Figure 5 on page 13, and complete the following steps to mount the CGA 351:

1. Select a flat surface on a vertical wall or instrument panel with sufficient space to hold the mounting plate with

both of the CGA 351 enclosures.

Note: Mount the system in an upright position, so that the sample inlet and outlet fittings are on the bottom of the

sensor enclosure.

be matched to a specific electronics enclosure). Refer to the identification tags on the

2. Using the mounting dimensions shown in Figure 5 on page 13, locate and prepare four (4) mounting holes or two

(2) horizontal mounting rails on the vertical surface.

3. Secure the system to the mounting surface with four (4) sets of mounting hardware. Be sure that the enclosures are

in a vertical position, with the inlet/outlet connectors on the bottom.

4. The flowmeter, which is fastened to the right side of the sensor enclosure, is connected to the discharge port on the

bottom of the unit with a length of 6mm stainless steel tubing. Make sure that the factory-installed Swagelok fittings are secure.

5. A flow control valve is attached to the inlet port on the bottom of the sensor enclosure with 6mm stainless steel

tubing and Swagelok fittings. Point the valve in the proper direction to receive the inlet piping from the sample system, and securely tighten the fittings.

2.4 Connecting the Sample System

The sample system should be located so that it is able to deliver a sample at a flow rate of 400 ±40 cc/min. For best results, mount the sample system as close as possible to the CGA 351. An ideal location would be on the same panel, just below the analyzer. If there are questions, consult with an applications engineer at the factory.

See Figure 5 on page 13, and complete the following steps to connect the sample system to the analyzer:

1. Using 6mm stainless steel tubing (or ¼” stainless steel tubing with adaptors), connect the gas source from the

sample system to the Swagelok fitting on the flow control valve at the inlet port on the analyzer.

2. Using 6 mm stainless steel tubing (or ¼” stainless steel tubing with adaptors), connect the Swagelok outlet fitting

at the top of the flowmeter on the analyzer to the gas discharge connection on the sample system.

Note: If desired, a suitable sample system may be ordered directly from the factory. The sample system would be

supplied fully assembled on a flat plate with four (4) mounting holes.

8 CGA 351 User’s Manual

Page 19

Chapter 2. Installation

2.5 Wiring the Analyzer

The system components which are housed in the sensor enclosure have already been wired at the factory. These include:

• Oxygen sensor (TB2)

• Thermocouple (TB2)

• Sensor furnace (TB2)

To completely wire the CGA 351 zirconium oxide oxygen analyzer, the following items must be connected:

• Serial port (TB1)

• Analog output (TB1)

• Alarm relays (TB1)

• Line power (TB3)

Refer to the wiring diagram shown in Figure 6 on page 14, while completing the instructions in this section.

WARNING! In order to meet CE Mark requirements, all cables must installed as described in Appendix B, CE

Mark Compliance.

IMPORTANT: For compliance with the European Union’s Low Voltage Directive (2006/95/EC), the CGA 351 requires

WARNING! To ensure safe operation of the CGA 351, the unit must be installed and operated as described in

To access the terminal printed circuit board, remove the cover below the digital display panel, which is fastened with six (6) Phillips head screws. The PC Board has terminal blocks TB1 (12 connections), TB2 (8 connections), and TB3 (3 connections) mounted on it. Proceed to the appropriate sub-section to wire each of these terminal blocks.

CGA 351 User’s Manual 9

Page 20

Chapter 2. Installation

2.5.1 Wiring the Outputs (TB1)

Terminal block TB1 contains connections for the CGA 351’s output signals. Specifically, the following signals are available at this terminal block:

• Serial port

• 0/4–20 mA, 0–2 V, or Namur analog output

• Alarm relays

To wire any or all of these output signals, complete the following steps:

1. Attach a cable or conduit with the appropriate number of conductors to an entry port on the bottom of the

electronics enclosure.

2. To connect a serial port from a personal computer, use the COMM pins on terminal block TB1 as follows:

a. Connect the transmit wire to pin b. Connect the receive wire to pin c. Connect the ground/return wire to pin

2. C.

3. To connect an analog output device, use the 4-20mA pins on terminal block TB1 as follows: a. Connect the input wire to the external device to pin b. Connect the output wire from the external device to pin

–.

4. To connect alarm device(s), use the ALARM 1 and/or ALARM 2 pins on terminal block TB1 as follows: a. Connect the input wire to the alarm-1 device to pin b. Connect the output wire from the alarm-1 device to pin

NO.

c. If desired, repeat sub-steps a and b to connect alarm-2.

5. Connect any shields to pin

Proceed to the next section to continue wiring the CGA 351.

10 CGA 351 User’s Manual

Page 21

Chapter 2. Installation

2.5.2 Wiring the Inputs (TB2)

Terminal block TB2 contains connections for the CGA 351’s sample measurement signals. Specifically, the following signals are routed to this terminal block:

• Zirconium oxide oxygen sensor

• Thermocouple

• Sensor furnace

All of the connections on terminal block TB2 have already been wired at the factory. In the event that one or more of these wires must be reconnected, complete the following steps:

1. Locate the leads from the zirconium oxide oxygen sensor. Connect these leads to terminal block TB2 as follows:

a. Connect the positive sensor wire (white - #1) to pin b. Connect the negative sensor wire (white - #2) to pin

–.

2. Locate the leads from the thermocouple. Connect these leads to terminal block TB2 as follows:

a. Connect the positive thermocouple wire (yellow - no number) to pin b. Connect the negative thermocouple wire (red - no number) to pin

–.

Note: The two thermocouple wires (red and yellow) are bound together in a brown sheath.

3. Locate the leads from the sensor furnace. Connect these leads to terminal block TB2 as follows:

a. Connect one furnace wire (white - #5) to pin b. Connect the other furnace wire (white - #6) to pin

Note: The polarity of the sensor furnace leads is not important.

4. Connect the ground wire (white - #G) and any shields to either of the pins labeled

This completes the wiring of terminal block TB2. Proceed to the next section to continue wiring the CGA 351.

CGA 351 User’s Manual 11

Page 22

Chapter 2. Installation

2.5.3 Wiring the Line Power (TB3)

Terminal block TB3 contains connections for the line power to the CGA 351. To wire the line power, complete the following steps:

WARNING! Before proceeding with the section, verify that the line power has been turned off at the external

disconnect device.

1. Attach a cable or conduit with the three line power conductors to an entry port on the bottom of the electronics enclosure.

CAUTION! Be sure that the input voltage to the CGA 351 complies with the value specified at the time of

purchase. If the voltage is incorrect, contact the factory immediately.

2. Connect the line power leads to terminal block TB3 as follows: a. Connect the line power lead (black) to pin b. Connect the neutral power lead (white) to pin

c. Connect the ground power lead (green) to the protective earth ground post, identified by .

This completes the wiring of the CGA 351 analyzer. Proceed to Chapter 3, Operation, for instructions on using the analyzer.

12 CGA 351 User’s Manual

Page 23

Chapter 1. Installation

(406)

11 1/2

(292)

9 1/2

(241)

3 1/2

(89)

6 3/4 (171)

7 3/8 (187)

6 3/8 (162)

SIDE VIEW

FRONT VIEW

(406)

14 1/4

(362)

7/8 (22)

8 1/4 (208)

3 7/8 (98)15 1/4 (387)

17 (432)

Ø1/2 (Ø12.7) 4pl

Mounting Hole

Mounting

Note: Dimensions are in inches (millimeters).

Plate

Figure 5: CGA 351 Mounting Dimensions

CGA 351 User’s Manual 13

Page 24

FUSE

TB3

TB2

TB1

COMM 4-20mA ALARM 1 ALARM 2 O2 TC HEATER 90-265 VAC

Group

COMM

4-20mA

ALARM 1

ALARM 2

Pin #

ALL

Description

RS232 Transmit (TX)

RS232 Receive (RX)

RS232 Return (RTN)

Any Shield or Ground

Analog Output (SIG+)

Analog Output (SIG-)

Normally Open (Standard Mode)

Common

Normally Closed (Failsafe Mode)

Normally Open (Standard Mode)

Common

Normally Closed (Failsafe Mode)

TB1 - OUTPUTS

HEATER

Thermocouple (-)

Furnace (+)

Any Gnd/Shield

Furnace (-)

Any Gnd/Sh

ield

Thermocouple (+)

Group

Description

TB2 - INPUTS

Pin #

Sensor (-)

Sensor (+)

ALL

6 (White)

5 (White)

N.A.

G (White)

N.A. (Red)

N.A.(Yellow)

2 (White)

1 (White)

Wire # (Color)

TB3 - POWER*

Pin #

5 x 20 mm

Size:

4 A, 250 V

FUSE

Type:

Rating:

TD (Time-Delay)

*90-265 VAC, 50/60 Hz, 900 W

NOTE: For proper operation, the unit must be powered by the voltage specified at the time of purchase.

Description

Line

Neutral

Color

Black

White

Outputs/PowerInputs Conduit

CCG+C21

21G

LNGNC NCNO NO

DS1

Conduit

Ground unit to protective earth post provided.

Chapter 1. Installation

Figure 6: CGA 351 Wiring Connections

CGA 351 User’s Manual 14

Page 25

Chapter 3. Operation

3.1 Introduction

The CGA 351 is an easily-operated monitoring d evice. Before applying power , make sure the system has been installed in accordance with the instructions given in Chapter 2, Installation.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

Allow the unit to warm up for at least thirty minutes prior to use. Check to see if it is hot. Observe all normal safety precautions. Specifically, do not exceed the maximum pressure and temperature ratings of the zirconium oxide oxygen sensor and the sample system.

This chapter includes discussions of the following topics:

• preventing common problems

• powering up the system

• configuring the digital display

• taking measurements

WARNING!

To ensure safe operation of the CGA 351, it must be installed and operated as described in this manual. In addition, be sure to follow all applicable local safety codes and regulations for installing electrical equipment.

3.2 Preventing Common Problems

Use the CGA 351 to accurately measure low oxygen levels. To avoid problems, observe the following:

• Check the calibration of the analyzer once or twice a week for the first month of operation and once every

2–3 months thereafter (see Chapter 4, Setup and Calibration, for instructions).

• Never use thread sealant on any connection in the sample gas flow path. Thread sealant gives off combustible

vapors that can cause reading errors.

• Do not handle the oxygen sensor with bare hands. Although some scratches on the platinum coating can be

tolerated, rubbing the coating should be avoided.

• Clean the oxygen sensor only by rinsing it with clean water , after the sensor has cooled. Scrubbing the oxygen

sensor or washing a hot sensor in cold water can damage or destroy it.

• Do not disturb the special sealant on the oxygen sensor nut and the inlet fittings. Any leakage in these areas

will cause inaccurate readings when measuring low oxygen levels.

CGA 351 User’s Manual 15

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Chapter 3. Operation

3.3 Powering Up the System

Before applying power, check the wiring connections and close both enclosures. Energize the external disconnect device to power up the CGA 351. For reliable readings, allow approximately two hours for the analyzer to reach temperature equilibrium before taking measurements.

WARNING!

IMPORTANT: For compliance with the European Union’s Low Voltage Directive (2006/95 /EC), th e CGA 351 requires

To prevent corrosion, the analyzer must be powered up immediately after introduction of the sample gas. If the analyzer is left installed without power, the unit’s components become susceptible to acid condensation that will cause corrosion.

If the power must be removed for more than thirty minutes, purge the analyzer through the inlet port with a continuous flow of instrument air at a rate of 400 ± 40 cc/min.

3.4 User Program Security

The CGA 351 has been equipped with a User Program (see the menu map in Figure 8 on page 25) that permits the setup and calibration of the instrument for optimum performance in any specific application. However, to prevent accidental changes to critical system parameters, four levels of security are imposed on the various submenus within the User Program. These are:

• Unlocked - access to these submenus is gained simply by pressing the [ESC] key. No password is required.

• Basic (locked) - access to these submenus is gained by pressing the [ESC], [ENT], and [ESC] keys in sequence.

Then, a password must be entered. (The default password is 2719.)

• General (locked) - access to these submenus is gained by pressing the [ESC], [ENT], and [ESC] keys in

sequence. Then, a password must be entered.

• Advanced (locked) - access to these submenus is gained by pressing the [ESC], [ENT], and [ESC] keys in

sequence. Then, a password must be entered.

Note: The passwords required for the three locked categories mentioned above are all different.

16 CGA 351 User’s Manual

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Chapter 3. Operation

Display Window

ESC Button ENTER Button

Cursor Control Keypad

POWER Button

3.5 Configuring the Digital Display

The digital display panel at the top of the electronics enclosure includes the components shown in Figure 7 below.

A typical display will be configured to the customer’s needs at the factory. If changes are required, follow the instructions in this section to complete the initial configuration of the digital display. As an aid in performing this task, refer to the menu map in Figure 8 on page 25.

3.5.1 Initial Screen Displays

Immediately upon power up, the digital display shows the following sequence of informational screens, as the meter performs its internal systems checks:

Figure 7: Digital Display Panel

BSeries Loader v1.05 This is a typical example of

Boot is Flash. Program CRC valid. Booting from Flash

the first initialization screen.

Scanning Hardware This is a typical example of

Found Image Slot 1

the second initialization screen.

Downloading Slot 1

CGA 351 User’s Manual 17

Scanning Hardware This is a typical example of

Initializing Machine Initializing UI

the final initialization screen.

Page 28

Chapter 3. Operation

3.5.1 Initial Screen Displays (cont.)

If the meter passes all of its internal system checks, the following screen appears:

1 Oxygen



This is a typical example of an initial screen.

Heater Warming

Note: The padlock icon at the upper right hand corner of the above display indicates that the User Program is locked

with password protection.

Before any data can be displayed, the meter must be configured for the desired display parameter(s). Enter the User Program by pressing the

IMPORTANT: In some applications, portions of the User Program may be locked to prevent end user access. If this is

[ESC] key and proceed as follows.

the case, entrance to these submenus requires a special key sequence and a password (see page 16).

3.5.2 Configuration Options

Cfg

Cal Opt Disp Upon entering the User

POWER ESC ENTER

Program, the already selected. Simply press

[ENTER]. (Notice that the [Disp] option is grayed out at

this time.

[Cfg] option is

Cfg

Cal Opt Disp To proceed with the [1: Cfg]

1: Cfg

option, press

[ENTER]. To

abort the operation, press

[ESC].

POWER ESC ENTER

From 1: Cfg A list of the available display

Oxygen

Temperature Sensor

inputs is shown. Use the [ and [

] keys to select the

desired input and press

[ENTER]. Oxygen has been

]

selected as an example.

POWER ESC ENTER

Note: The [CJC Temp] and [Duty Cycle] options are also available in the above list box.

18 CGA 351 User’s Manual

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Chapter 3. Operation

3.5.2 Configuration Options (cont.)

From 1: Cfg Oxygen A list of the available unit

ppm

pcnt AF

POWER ESC ENTER

types is shown. Use the [ and [

] keys to select the

desired units (parts per million or percent) and press

If either of the Temperature inputs is selected for display, °C and °F are available as the unit types. For the Sensor and Duty Cycle inputs, mV and pcnt, respectively, are the only available unit types.

From 1: Cfg Ox..pcnt A list of the available output

*0: Display

*0: Fault Alarm

Add Remove

Cancel

devices is shown. Follow the instructions below to select the desired outputs.

]

[ENTER].

POWER ESC ENTER

Note: The

[0:Analog Output], [2:Alarm-1], [2:Alarm-2], [2:Alarm-3] and [2:Alarm-4] options are also available in the

above list box.

To select the desired output(s) from the previous list box, complete the following steps:

1. Use the [

] and [] keys to highlight a specific output. For this example, make sure that [0: Display] is selected as

one of the outputs.

2. Use the [

] and [] keys to select “Add” or “Remove” and press the [ENTER] key to change the status of the

selected output. An output is selected if an asterisk (*) appears to its left.

3. When all of the desired outputs have been selected, use the [

] and [] keys to select “OK” and press [ENTER].

1 Oxygen Press [ESC] four times to

2.71 ppm

return the display to the actual set configuration.

POWER ESC ENTER

Notice that the newly-configured display shows the slot number and the input parameter on the top line, and the current live value along with the unit type are displayed in the center of the screen.

Note: See Chapter 4, Setup and Calibration, for instructions on how to adjust the display contrast.

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Chapter 3. Operation

ARng

%O2()AR Zero()–

AR Span()AR Zero()–

----------------------------------------------------------

100× 75%==

3.5.3 Using the Auto Range Feature

The Auto Range feature includes three unit types:

• ARng (Auto Range %): the ratio of the current oxygen reading to the currently active Auto Range, expressed

as a percentage

• AR-A (Auto Range Alarm A): automatically set to a value of 0 or 1

• AR-B (Auto Range Alarm B): automatically set to a value of 0 or 1

As an example of how these units work with the default values listed in T a ble 3 on page 44, consider a situation where the current oxygen reading is 7.5%. The Auto Range feature would select the current active range as Range 3 in the table. Then,

(1)

This means that the current oxygen reading represents 75% of the currently active Auto Range. In addition to the ARng value calculated above, AR-A = 0 and AR-B = 1, as shown in the table.

After programming the Auto Ranges, the CGA 351 must be configured to properly h andle the Auto Range output. To accomplish this, the following outputs must be reprogrammed:

• Alarm A and Alarm B

• 4-20 mA analog output

3.5.4 Configuring the Alarms

The first step in setting up the alarms is to assign the correct unit types. T o accomplish this, proceed as follows from the Main Menu:

Cfg

Cal Opt Disp Upon entering the User

POWER ESC ENTER

Cfg

Cal Opt Disp To proceed with the [1: Cfg]

1: Cfg

Program, the already selected. Simply press

[ENTER].

option, press

[Cfg] option is

[ENTER].

POWER ESC ENTER

20 CGA 351 User’s Manual

Page 31

3.5.4 Configuring the Alarms (cont.)

From 1: Cfg A list of the available display

Oxygen

Temperature Sensor

POWER ESC ENTER

From 1: Cfg Oxygen A list of the available unit ARng

AR-A

AR-B

POWER ESC ENTER

Note: The [ppm], [pcnt] and [AF] options are also available above.

inputs is shown. Use the [ and [ Oxygen input and press

[ENTER].

types is shown. Use the [ and [ option and press

Chapter 3. Operation

]

] keys to select the

]

] keys to select the AR-A

[ENTER].

From 1: Cfg Ox..AR-A Follow the instructions on

*2: Alarm-1

*2 Alarm-2

Add Remove

POWER ESC ENTER

Cancel

page 19 to select Alarm-1 as the desired output for the AR-A unit type.

• Repeat the previous steps to assign the AR-B unit type to Alarm-2.

Detailed instructions for setting up the alarms are provided in Chapter 4, Setup and Calibration. Simply follow those instructions to program the alarm settings listed in Table 1 below.

Table 1: Available Alarm Settings

Alarm # Trip Type Trip Value Deadband

1 Above 1.0 0.0 2 Above 1.0 0.0

The alarms will now respond as described in Table 3 on page 44. That is, Alarm-1 will trip when Auto Range #2 or Auto Range #4 is active, while Alarm-2 will trip when Auto Range #3 or Auto Range #4 is active.

Note: If fewer than 3 Auto Ranges are being used, Alarm 2 may be used for other purposes.

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Chapter 3. Operation

3.5.5 Configuring the Analog Output

In a manner similar to that used to configure the alarms in the previous section, program the analog output with the following settings:

Note: Refer to Chapter 4, Setup and Calibration, for detailed programming instructions for the analog output.

• unit type: ARng

• zero set point: 0%

• span set point: 100%

When configured as specified above, the 4-20 mA analog output signal represents 0-100% of the currently active Auto Range.

3.5.6 Switching Display Windows

After the display has been configured, the meter actually maintains multiple display windows. Although only one window can be displayed at any given time, it is easy to switch to one of the other windows via the User Program. Enter the User Program by pressing the

[ESC] key.

Cfg Cal Opt

POWER ESC ENTER

Cfg Cal Opt

Disp

1: Oxygen pcnt

1: Temperature DegF 1: Oxygen ppm

POWER ESC ENTER

1 Oxygen

3.27 pcnt

Notice that the fourth option,

[Disp], is now available. Use

the [

] and [] keys to select

[Disp] and press [ENTER].

A list of the available windows is shown. Use the [

] and []

keys to select the desired window and press

[ENTER].

After pressing [ENTER] at the previous prompt, press [ESC] and the alternate display appears.

POWER ESC ENTER

22 CGA 351 User’s Manual

Page 33

Chapter 3. Operation

3.5.6 Switching Display Windows (cont.)

When configuring the digital display options, the following two factors must be considered:

• Only the digital display and the fault alarm options can be simultaneously assigned to more than one

parameter. This is because they are virtual devices that are stored in memory.

• The analog output, alarm-1, alarm-2, alarm-3 and alarm-4 options can be assigned to only one parameter at

any given time. This is because they are linked to a specific physical device.

One must be careful about making changes in the User Program, while data is being displayed. If the currently selected display input is accidentally deselected, the screen reverts to the following:

x_Unassigned

POWER ESC ENTER

Although the meter is still collecting data, the digital display does not know which information to show. Simply re-select the appropriate input parameter, through the

[Disp] menu option, to restore the digital display.

3.6 Converting mV to Oxygen Concentration

Although the digital display can show the oxygen concentration in ppm or pcnt and the oxygen sensor output in mV, only one parameter can be displayed at any given time. Therefore, it may sometimes be helpful to manually convert a reading from one form to another. Table 2 below provides such information for the full range of the CGA 351, at the typical operating temperature of 700°C.

Table 2: Oxygen Units Conversions

Sensor (mV) Oxygen (pcnt) Oxygen (ppm)

–32.8 100 1,000,000

15.4 10 100,000

63.7 1 10,000

111.9 0.1 1,000

160.2 0.01 100

208.4 0.001 10

256.7 0.0001 1

304.9 0.00001 0.1

The data in Table 2 above was calculated with the Nernst equation. See Appendix A, The Nernst Equation, for details on performing such calculations.

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Chapter 3. Operation

3.7 Powering Down

When it becomes necessary to power down the CGA 351 for service, proceed as follows:

1. Press the [POWER] button just below the digital display.

2. Place the external disconnect device into the OFF position.

CAUTION!

Never open the door on the sensor enclosure until the sensor has cooled to ambient temperature (in about two hours). Rapid cooling of a hot sensor will cause cracks in the ceramic sensor.

Any required service procedures may now be performed.

24 CGA 351 User’s Manual

Page 35

ESC*

Opt

Contrast

Analog Output

Backlight

Comm

Fault Alarm

Non Fail-Safe

Fail-Safe

Off

Timed

Span Setpoint

AOut Type

Zero Setpoint

Test

Zero Trim

Span Trim

0-2V

0-20mA

4-20mA

Namur

Node ID

Lock Menus

Setup

Lock All

Versions

Load Slot

Erase Slot

Load Main

Erase Main

Setpoint

Prop Band

Temp Control

Int. Time

Default

Setup

Cal

Diag

Impedance

ppm

pcnt

Heater

Alarm-2

Alarm-3

Trip Value

Trip Type

Test

Fail-Safe

Enter Value

Above

Below

Norma

Trip

Reset

Non Fail-Safe

Fail-Safe

1:Cfg

Sensor

Temperature

Oxygen

CJC Temp

Duty Cycle

0: Fault Alarm

0: Display

2: Alarm-1

2: Alarm-2

ARng

AR-A

deg C

deg F

deg C

deg F

pcnt

Disp

[*as selected in 1: Cfg menu]

Cfg

Cal

Alarms

2: Cal

Setup

1: Cal

User

Baud Rate

Data Length

Parity

Stop Bits

Comm Type

Security Level Key Sequence

Password?

Yes

Unlocked

Operator - Locked

General - Locked

Factory - Locked

ESC

ESC, ENT, ESC

[*submenu security levels customized for each unit - see table below]

Air Offset

2: Alarm-4

2: Alarm-3

Alarm-4

Alarm-1

AR-B

ppm

pcnt

Auto Range

Line Voltage

PCNT Table

PPM Table

Zero

Span

Chapter 2. Chapter 3. Operation

CGA 351 User’s Manual 25

Figure 8: CGA 351 Menu Map

Page 36

[no content intended for this page]

Chapter 3. Operation

CGA 351 User’s Manual 26

Page 37

Chapter 4. Setup and Calibration

4.1 Introduction

Although the CGA 351 is set up at the factory with default operational parameter values that are suitable for many applications, the User Program provides a means for customizing many of the setup parameters. Proper setup of the analyzer is very important to ensure accurate data readings.

Generally , changes in calibration result from aging of the zirconium oxide oxygen sensor. Within limits, oxygen reading errors can usually be compensated for by making minor temperature adjustments. The zirconium oxide oxygen sensor should be calibrated once or twice a week for the first month of operation and every 2–3 months thereafter.

WARNING!

Follow the instructions in this chapter exactly to ensure proper setup and calibration of the CGA 351.

4.2 Accessing the User Program

To ensure accurate oxygen level readings and to make use of the alarm relays, serial port and analog output, the appropriate entries must be made in the User Program. Follow the instructions in this section to accomplish these tasks.

Enter the User Program (see the menu map in Figure 8 on page 25) by pressing the Program, press

Note: Some submenus may be locked and will require a special key sequence and a password for entry (see “User

Program Security” on page 16).

[ESC] at any time to abort the current operation.

Cfg

Cal

Opt Disp Use the [] and [] keys to

select

[Cal] and press

[ENTER]. (NOTE: this screen

shows the already being configured.)

[Disp] option as

[ESC] key. While in the User

POWER ESC ENTER

As an aid in programming the CGA 351, refer to the menu map, Figure 8 on page 25. Proceed directly to the appropriate section to set up and/or calibrate the analyzer.

CGA 351 User’s Manual 27

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Chapter 4. Setup and Calibration

4.3 The [Cal] Menu

After entering the User Program, access the [Cal] submenu to set the following parameters:

• Alarm-1 relays

• Alarm-2 relays

• Alarm-3 relays

• Alarm-4 relays

• Temperature controls

The calibration and diagnostic portions of this submenu are discussed later in this chapter. Proceed to the appropriate section for specific instructions on the topic of interest.

4.4 Setting Up the Alarm Relays

To set up the CGA 351’s external alarm relays, corresponding to the wiring terminals on TB1, proceed as follows:

Cal

Cfg 1: Cal 2: Cal

POWER ESC ENTER

Setup Use the [] and [] keys to Setup

Slct Cal Menu Item

POWER ESC ENTER

Setup Use the [] and [] keys to Alarms

Opt Disp Use the [] and [] keys to

select

[2: Cal] and press

[ENTER].

select

[Setup] and press

[ENTER].

select

[Alarms] and press

[ENTER].

POWER ESC ENTER

28 CGA 351 User’s Manual

Page 39

4.4 Setting Up the Alarm Relays (cont.)

Chapter 4. Setup and Calibration

Alarms Use the [

Alarm-1

Alarm-2 Alarm-3

POWER ESC ENTER

Note: The [Alarm-4] option is also available in the above list box.

The following alarm features may be set in this submenu:

select

[ENTER].

] and [] keys to

[Alarm-1] and press

• Trip Type: specifies whether the alarm relay triggers when the live measurement value moves above or below

the trip value.

• Trip Value: specifies the live measurement value at which the alarm relay triggers.

• Deadband Value: specifies a small range of live measurement values, centered on the trip value, for which the

alarm relay does not trigger or reset. This prevents the alarm relay from repeatedly triggering and resetting when the live measurement value is very close to the trip value.

• Test: permits the manual triggering and resetting of the alarm relay, to verify that it is working properly.

• Fail-Safe: specifies whether the alarm relay is energized during normal operation or during an error condition.

Go to the appropriate sub-section to set the desired alarm feature.

Note: The setup of Alarm-1 is used as an example in this manual. To set up Alarm-2, -3 or -4, return to the pr evious

prompt and select the

desired option. Then, repeat the remaining steps.

CGA 351 User’s Manual 29

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Chapter 4. Setup and Calibration

4.4.1 Setting the Trip Type

Enter the alarm setup menu and proceed as follows:

Alarms..Alarm-Feat Use the [

Trip Type

Trip Value

select

[ENTER].

] and [] keys to

[Trip Type], and press

Deadband Value

POWER ESC ENTER

Note: The

[Test] and [Fail-Safe] options are also available in the above list box.

Alarms A..Trip-Type Use the [] and [] keys to

Above

Below

select the desired trip type, and press

[ENTER].

Above with Fault

POWER ESC ENTER

Note: The

[Below with Fault] option is also available in the above list box.

The meter now automatically returns to the “Alarm-Features” prompt. Either press [ESC] until you exit the User Program or proceed to the appropriate section to continue setting up the alarms.

30 CGA 351 User’s Manual

Page 41

4.4.2 Setting the Trip Value

Enter the alarm setup menu and proceed as follows:

Chapter 4. Setup and Calibration

Alarms..Alarm-Feat Use the [ Trip Typ e

Trip Value

select

[ENTER].

] and [] keys to

[Trip Value], and press

Deadband Value

POWER ESC ENTER

Note: The

[Test] and [Fail-Safe] options are also available in the above list box

At the next prompt, enter the desired trip point value.

Alarms..Trip Value Using the [] and [] keys,

ppm

000.00 p

POWER ESC ENTER

position the cursor under the desired character. Then, use the [

] and [] keys to

increment the value. When done, press

[ENTER].

The meter now automatically returns to the “Alarm-Features” prompt. Either press Program or proceed to the appropriate section to continue setting up the alarms.

[ESC] until you exit the User

CGA 351 User’s Manual 31

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Chapter 4. Setup and Calibration

4.4.3 Setting the Deadband Value

Enter the alarm setup menu and proceed as follows:

Alarms..Alarm-Feat Use the [ Trip Typ e Trip Value

select press

] and [] keys to

[Deadband Value], and

[ENTER].

Deadband Value

POWER ESC ENTER

Note: The

[Test] and [Fail-Safe] options are also available in the above list box.

At the next prompt, enter the desired deadband value.

Alar..Trip-Deadband Using the [] and [] keys,

ppm

000.00 p

POWER ESC ENTER

position the cursor under the desired character. Then, use the [

] and [] keys to

increment the value. When done, press

[ENTER].

The meter now automatically returns to the “Alarm-Features” prompt. Either press [ESC] until you exit the User Program or proceed to the appropriate section to continue setting up the alarms.

32 CGA 351 User’s Manual

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Chapter 4. Setup and Calibration

4.4.4 Testing the Alarm Relays

Enter the alarm setup menu. T o verify that the alarm relay is functioning properly, the alarm may be operated manually as follows:

Alarms..Alarm-Feat Use the [ Trip Value Deadband Value

select

[ENTER].

] and [] keys to

[Test], and press

Test

POWER ESC ENTER

Note: The

The following options are available in the [

[Trip Type] and [Fail-Safe] options are also available in the above list box.

TEST] submenu:

• Normal: sets the alarm relay to its proper state, as dictated by the current live measurement value.

IMPORTANT: Always return the alarm relay to this state at the conclusion of the testing.

• Trip: manually triggers the alarm relay to its “ON” state.

• Reset: manually returns the alarm relay to its “OFF” state.

Alarms..Alarm-Test Use the [] and [] keys to Normal

Trip

Reset

select the desired option. Press done.

TEST

[ENTER] when

POWER ESC ENTER

The meter now automatically returns to the “Alarm-Features” prompt. Either press [ESC] until you exit the User Program or proceed to the appropriate section to continue setting up the alarms.

CGA 351 User’s Manual 33

Page 44

Chapter 4. Setup and Calibration

4.4.5 Selecting the Operating Mode

Enter the alarm setup menu and proceed as follows:

Alarms..Alarm-Feat Use the [ Deadband Value Test

select

[ENTER].

] and [] keys to

[Fail-Safe], and press

Fail-Safe

POWER ESC ENTER

Note: The [Trip Type] and [Trip Value] options are also available in the above list box.

At the next prompt, enter the desired operating mode.

Note: In fail-safe mode, the alarm relay is constantly energized during normal operation and is de-energized when

the trip point is crossed. In normal (non fail-safe) operation, the alarm relay is energized only when the trip point is crossed.

Alarms..Fail-Safe Use the [] and [] keys to

Non Fail-Safe

Fail-Safe

select the desired operating mode and press

[ENTER].

POWER ESC ENTER

The meter now automatically returns to the “Alarm-Features” prompt. Press [ESC] until you exit the User Program.

34 CGA 351 User’s Manual

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Chapter 4. Setup and Calibration

4.5 Setting the Temperature Controls

To configure the temperature control circuits of the CGA 351, complete the following instructions.

CAUTION!

Improper temperature controls settings can seriously degrade the performance of the instrument. Never change these settings without specific instructions from GE.

Setup

Cal

Opt Disp Use the [] and [] keys to

select

[1: Cal] and press

[ENTER].

Cal Diag Use the [] and [] keys to

select

[Setup] and press

[ENTER].

Cfg

1: Cal

2: Cal

POWER ESC ENTER

Slct Cal Menu Item

POWER ESC ENTER

Setup

Temp Control

Auto Range

Cal Use the [] and [] keys to

select

[T emp Control] and press

[ENTER].

Line Voltage

POWER ESC ENTER

Proceed to the appropriate sub-section to program the desired temperature control feature.

CGA 351 User’s Manual 35

Page 46

Chapter 4. Setup and Calibration

4.5.1 Entering the Setpoint

CAUTION! Improper temperature controls settings can seriously degrade the performance of the

instrument. Never change these settings without specific instructions from GE.

Enter the temperature control menu as described there and proceed as follows:

Temp-Cntrl Use the [

Setpoint

Sensor Temp

select [Setpoint] and press

[ENTER].

] and [] keys to

Air Offset

POWER ESC ENTER

Note: The [Select Gas Type], [Prop Band], [Int Time]

, [Max.Duty Cycle] and [Default] options are also available in

the above list box.

At the next prompt, enter the desired operating temperature for the analyzer. Usually, this is a 700–780°C oxygen sensor temperature.

IMPORTANT: Calibrating the meter automatically adjusts the value of the setpoint temperature.

Temp-Cntrl...Set Point Using the [] and [] keys, Setpoint 000 p

POWER ESC ENTER

position the cursor under the desired character. Then, use the [

] and [] keys to

increment the value. When done, press

[ENTER].

Temp..Invalid-Output This message indicates that Modifying value may cause invalid output

changes in this menu will alter the live data output. Press

[ENTER] to continue.

OK Cancel

POWER ESC ENTER

Tem..Unit-Measuring This message indicates that Unit measuring Accept changes?

Yes No Cancel

POWER ESC ENTER

changes in this menu will alter the live data output. To accept the new value, use the [ [

] keys to select [Yes] and

press

[ENTER].

] and

The meter now automatically returns to the “Temp. Control” prompt. Either press [ESC] until you exit the User Program or proceed to the appropriate section to continue setting up the temperature control.

36 CGA 351 User’s Manual

Page 47

4.5.2 Entering the Sensor Temperature

Enter the temperature control menu and proceed as follows:

Chapter 4. Setup and Calibration

Temp-Cntrl Use the [ Setpoint

Sensor Temp

Air Offset

POWER ESC ENTER

Note: The [Select Gas Type], [Prop Band], [Int Time]

, [Max.Duty Cycle] and [Default] options ar e also available in th e

above list box.

At the next prompt, enter the desired value for the air offset.

Temp-C . . Sensor-Temp Using the [] and [] keys, Sensor Temp 000 p

POWER ESC ENTER

] and [] keys to

select [Sensor Temp] and press

[ENTER].

position the cursor under the desired character. Then, use the [

] and [] keys to

increment the value. When done, press

[ENTER].

Tem..Unit-Measuring This message indicates that Unit measuring Accept changes?

Yes No Cancel

POWER ESC ENTER

The meter now automatically returns to the “Temp. Control” prompt. Either press [ESC]

changes in this menu will alter the live data output. To accept the new value, use the [ [

] keys to select [Yes] and

press

[ENTER].

] and

until you exit the User

Program or proceed to the appropriate section to continue setting up the temperature control.

CGA 351 User’s Manual 37

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Chapter 4. Setup and Calibration

4.5.3 Setting the Air Offset

CAUTION! Improper temperature controls settings can seriously degrade the performance of the

instrument. Never change these settings without specific instructions from GE.

Enter the temperature control menu and proceed as follows:

Temp-Cntrl Use the [ Sensor Temp

Air Offset

Select Gas Type

POWER ESC ENTER

Note: The [Setpoint], [Prop Band], [Int Time]

, [Max.Duty Cycle] and [Default] options are also available in the above

list box.

At the next prompt, enter the desired value for the air offset.

Temp-Cn . . Air-Offset Using the [] and [] keys,

Air Offset

0000.00 p

POWER ESC ENTER

Tem..Unit-Measuring This message indicates that Unit measuring Accept changes?

Yes No Cancel

POWER ESC ENTER

] and [] keys to

select [Air Offset] and press

[ENTER].

position the cursor under the desired character. Then, use the [

] and [] keys to

increment the value. When done, press

[ENTER].

changes in this menu will alter the live data output. To accept the new value, use the [ [

] keys to select [Yes] and

press

[ENTER].

] and

The meter now automatically returns to the “Temp. Control” prompt. Either press [ESC]

until you exit the User

Program or proceed to the appropriate section to continue setting up the temperature control.

38 CGA 351 User’s Manual

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Chapter 4. Setup and Calibration

4.5.4 Selecting the Gas Type

CAUTION! Improper temperature controls settings can seriously degrade the performance of the

instrument. Never change these settings without specific instructions from GE.

Enter the temperature control menu and proceed as follows:

Temp-Cntrl Use the [ Air Offset

Select Gas Type

Prop Band

POWER ESC ENTER

Note: The [Setpoint], [Sensor Temp], [Int Time]

, [Max.Duty Cycle] and [Default] options are also available in the

above list box.

Te . . Select-Gas-Type Use the [] and [] keys to

Coal

Oil Propane - Butane

POWER ESC ENTER

Note: The [Natural Gas], [Coke Oven Gas], [Methane]

Tem . . Enter_HC_Ratio Using the [] and [] keys,

Enter_HC_Ratio

0.0000 p

POWER ESC ENTER

] and [] keys to

select [Select Gas Type] and press

[ENTER].

select the type of gas. When done, press

, and [Other] options are also available in the above list box.

[ENTER].

position the cursor under the desired character. Then, use the [

] and [] keys to

increment the value. When done, press

[ENTER].

CGA 351 User’s Manual 39

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Chapter 4. Setup and Calibration

4.5.5 Selecting the Proportional Band

CAUTION! Improper temperature controls settings can seriously degrade the performance of the

instrument. Never change these settings without specific instructions from GE.

Enter the temperature control menu and proceed as follows: Note: See “The Heater Control Circuit” on page 6 for a discussion of the proportional band.

Temp-Cntrl Use the [ Air Offset Select Gas Type

select [Prop Band] and press

[ENTER].

Prop Band

POWER ESC ENTER

Note: The [Setpoint], [Sensor Temp], [Int Time]

, [Max.Duty Cycle] and [Default] options are also available in the

above list box.

At the next prompt, enter the desired value for the proportional band.

Temp-Cntrl Se . . Prop Using the [] and [] keys, Prop 0000 p

position the cursor under the desired character. Then, use the [

] and [] keys to

increment the value. When done, press

POWER ESC ENTER

Tem . .Unit-measuring This message indicates that Unit measuring Accept changes?

Yes No Cancel

changes in this menu will alter the live data output. To accept the new value, use the [ [

] keys to select [Yes] and

press

POWER ESC ENTER

] and [] keys to

[ENTER].

] and

[ENTER].

The meter now automatically returns to the “Temp. Control” prompt. Either press [ESC]

until you exit the User

Program or proceed to the appropriate section to continue setting up the temperature control.

40 CGA 351 User’s Manual

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Chapter 4. Setup and Calibration

4.5.6 Setting the Integration T ime

CAUTION! Improper temperature controls settings can seriously degrade the performance of the

instrument. Never change these settings without specific instructions from GE.

Enter the temperature control menu, as described on page 35, and proceed as follows:

Note: See “The Heater Control Circuit” on page 6 for a discussion of the integration time.

Temp-Cntrl Use the [ Prop Band

Int Time

select [Int Time] and press

[ENTER].

Max Duty Cycle

POWER ESC ENTER

Note: The [Setpoint]

, [Sensor Temp], [Air Offset], [Select Gas Type] and [Default] options are also available in the

above list box.

At the next prompt, enter the desired value for the integration time.

Temp-Cntrl . . Int-Time Using the [] and [] keys,

Int Time

0000 p

position the cursor under the desired character. Then, use the [ increment the value. When done, press

POWER ESC ENTER

Tem . . Unit-measuring This message indicates that Unit measuring Accept changes?

Yes No Cancel

changes in this menu will alter the live data output. To accept the new value, use the [ [

] keys to select [Yes] and

press

POWER ESC ENTER

] and [] keys to

[ENTER].

] and

[ENTER].

CGA 351 User’s Manual 41

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Chapter 4. Setup and Calibration

4.5.7 Setting the Maximum Duty Cycle

CAUTION! Improper temperature controls settings can seriously degrade the performance of the

instrument. Never change these settings without specific instructions from GE.

Enter the temperature control menu and proceed as follows:

Note: The value selected for this parameter indicates the percentage of time that the heater receives power. Thus, a

larger number results in a faster heat up to operating temperature, while a smaller number results in a slower heat up.

Temp-Cntrl Use the [ Int. Time

Max. Duty Cycle

Default

POWER ESC ENTER

Note: The

[Setpoint], [Sensor Temp], [Air Offset], [Select Gas Type] and [Prop Band] options are also availabl e in the

above list box.

At the next prompt, enter the desired value for the duty cycle.

Temp-Cn . . Duty Cycle Using the [] and [] keys, Duty Cycle 000 p

POWER ESC ENTER

Tem . . Unit-Measuring This message indicates that Unit measuring Accept changes?

Yes No Cancel

POWER ESC ENTER

] and [] keys to

select [Max. Duty Cycle] and press

[ENTER].

position the cursor under the desired character. Then, use the [

] and [] keys to

increment the value. When done, press

[ENTER].

changes in this menu will alter the live data output. To accept the new value, use the [ [

] keys to select [Yes] and

press

[ENTER].

] and

The meter now automatically returns to the “Temp. Control” prompt. Either press

[ESC] until you exit the User

Program or proceed to the appropriate section to continue setting up the temperature control.

42 CGA 351 User’s Manual

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Chapter 4. Setup and Calibration

4.5.8 Restoring the Default Values

T o reset the Setpoint, Proportional Band, Integration T ime and Max. Duty Cycle parameters to their default values, enter the temperature control menu and proceed as follows:

IMPORTANT: Restoring the default values invalidates the existing calibration. It will be necessary to recalibrate the

meter (see “Calibrating the CGA 351” on page 62) before reliable readings are obtained.

From Temp Control Use the [ Int. Time Max Duty Cycle

select [Default] and press

[ENTER].

] and [] keys to

Default

POWER ESC ENTER

Note: The

[Setpoint], [Air Offset] and [Prop Band] options are also available in the above list box.

Tem..Unit-Measuring This message indicates that Unit measuring Accept changes?

Yes No Cancel

POWER ESC ENTER

changes in this menu will alter the live data output. To accept the new value, use the [ [

] keys to select [Yes] and

press

[ENTER].

The meter now automatically returns to the “Temp. Control” prompt. Press

] and

[ESC] until you exit the User Program.

CGA 351 User’s Manual 43

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Chapter 4. Setup and Calibration

4.6 Auto Range Analog Output

This CGA 351 Zirconia Oxygen Analyzer has been configured with a new software version that permits the instrument to automatically select the appropriate 4-20 mA analog output range from among 1-4 predefined ranges. To make this feature as flexible as possible, the user has the ability to program the following parameters for the Auto Range output:

• Number of ranges to be used (1, 2, 3, or 4)

• Units for each range (ppm or pcnt)

• Zero and span points for each range

After the Auto Range feature has been programmed, the two CGA 351 Alarms will indicate the specific range that is currently active.

4.6.1 Factory Defaults

For convenience, the CGA 351 is pre-programmed at the factory with Auto Range default values that are suitable for many applications. These values are listed in Table 3 below:

Table 3: Auto Range Default Values

Range Units Zero Span AR-A* AR-B*

1 ppm 0.00 10.0 0 0 2 ppm 0.00 1000.0 1 0 3 pcnt 0.00 10.00 0 1 4pcnt0.00100.01 1

* These unit types are NOT programmable by the user.

For example, Range 3 is set for 0-10 pcnt oxygen and its use is indicated by AR-A having a value of 0 and AR-B having a value of 1 (the meaning of these alarm unit types will become clear in the following sections). Proceed to the next sections to learn how to use the Auto Range feature and how to modify the factory default settings.

4.6.2 Programming the Auto Ranges

T o change the default values for the Auto Range feature shown in Table 3 above, follow the instructions in this section to set these parameters:

• Number of ranges

• Units

• Zero and span points

44 CGA 351 User’s Manual

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4.6.2a Choosing the Number of Ranges

To select the number of ranges, proceed as follows from the Main Menu:

Chapter 4. Setup and Calibration

Cfg

Cal

Opt Disp Use the [] and [] keys to

1: Cal

2: Cal

POWER ESC ENTER

Setup

Cal Diag Use the [] and [] keys to

Slct Cal Menu Item

POWER ESC ENTER

Setup

Cal Use the [] and [] keys to

Temp Control

Auto_Range

Line_Voltage

select

[1: Cal] and press

[ENTER].

select

[Setup] and press

[ENTER].

select

[Auto Range] and press

[ENTER].

POWER ESC ENTER

Num_of_Auto_Ranges Use the [] and [] keys to Enter Num of Range x

increment the value to a number between 1 and 4. When done, press

[ENTER].

POWER ESC ENTER

Note: If a number less than 1 is entered above, the setting will default to 1 Auto Range. If a number greater than 4 is

entered above, the setting will default to 4 Auto Range.

CGA 351 User’s Manual 45

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Chapter 4. Setup and Calibration

4.6.2b Selecting the Units

To select the units to be used, proceed as follows:

A . . Auto_Range_Units Use the [

PCT_Table

PPM_Table

POWER ESC ENTER

Note: Entry of the zero and span points for all ranges will be made in the units selected above. Internally, the

CGA 351 will automatically convert the data into the non-selected units.

select the desired units table and press

] and [] keys to

[ENTER].

4.6.2c Entering the Zero and Span Points

To enter the zero and span points, proceed as follows:

Num_of_Auto_Ranges Use the [] and [] keys to Zero_Pct. Span_Pct. xx.xxxxx xxx.xxxx

 1..4

POWER ESC ENTER

position the cursor. Then, use the [

] and [] keys to

increment the character to the desired value. When done, press

[ENTER].

The above step will be repeated as many times as necessary to complete the table for the total number of ranges selected on the previous page.

4.7 The [Opt-User] Menu

After entering the User Program, access the [Opt-User] submenu to perform the following operations:

• Setting the fault alarm type

• Setting up the analog output

• Adjusting the display contrast

• Setting the display backlight

• Configuring the serial port

Proceed to the appropriate section for specific instructions on the topic of interest.

46 CGA 351 User’s Manual

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4.8 Setting Fault Alarm Type

To set up the fault alarm, enter the User Program and proceed as follows:

Opt

Cfg Cal

POWER ESC ENTER

Disp Use the [] and [] keys to

select

[Opt] and press

[ENTER].

Chapter 4. Setup and Calibration

Note: The

Cfg Cal

User

Setup

Opt

Disp A list of the available options

is shown. Use the [ keys to select

[ENTER].

[User] and press

] and []

Lock Menus

POWER ESC ENTER

[Lock All] and [Versions] options are also available in the above list box.

User Use the [] and [] keys to

select

Fault Alarm

Analog Output

[Fault Alarm] and press

[ENTER].

Contrast

POWER ESC ENTER

[Backlight] and [Comm] options are also available in the above list box.

User Fault-Alarm Use the [] and [] keys to

Non Fail-Safe

Fail-Safe

select the desired alarm type and press

[ENTER].

POWER ESC ENTER

The meter now automatically returns to the “User” prompt. Either press [ESC] until you exit the User Program or proceed to the appropriate section to continue setting up the user options.

CGA 351 User’s Manual 47

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Chapter 4. Setup and Calibration

4.9 Setting Up the Analog Output

To set up the CGA 351’s analog output, enter the User Program and proceed as follows:

Opt

Cfg Cal

POWER ESC ENTER

Disp Use the [] and [] keys to

select

[Opt] and press

[ENTER].

Cfg Cal

User

Setup Lock Menus

POWER ESC ENTER

User Use the [] and [] keys to Fault Alarm

Analog Output

Contrast

POWER ESC ENTER

Note: The

The following procedures may be performed in this submenu:

[Backlight] and [Comm] options are also available in the above list box.

Opt

Disp A list of the available options

is shown. Use the [ keys to select

[ENTER].

select

[Analog Output] and

press

[ENTER].

[User] and press

] and []

• Analog Output Type: configure the analog output for a 0-20 mA, 4-20 mA, 0-2 V, or Namur type.

• Zero Setpoint: enter the live measurement value that corresponds to the low end of the analog output range.

• Span Setpoint: enter the live measurement value that corresponds to the high end of the analog output range

minus the zero setpoint.

• Test: specify a fixed percentage of the analog output range and verify that the correct value is generated.

• Zero Trim: adjust the actual output to equal the low end of the analog output range.

• Span Trim: adjust the actual output to equal the high end of the analog output range minus the zero setpoint.

Proceed to the appropriate sub-section to program the desired analog output feature.

48 CGA 351 User’s Manual

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4.9.1 Selecting the Analog Output Type

Enter the analog output setup menu and proceed as follows:

Chapter 4. Setup and Calibration

User Aout Use the [

Aout Type

Zero Setpoint

select

[ENTER].

] and [] keys to

[Aout Type], and press

Span Setpoint

POWER ESC ENTER

Note: The

[Test], [Zero Trim] and [Span Trim] options are also available in the above list box.

User Aout Aout-Type Use the [] and [] keys to 0-20mA

4-20mA

select the desired device type, and press

[ENTER].

0-2V

POWER ESC ENTER

Note: The [0-2V] option is software-selected and therefore there is no need for hardware modifications to output

0-2 volts DC.

The

[Namur] option is also available in the above list box.

The Namur NE43 specification requires a 4-20 mA output to be clamped in specific bands to indicate out-of-range errors.

The 0-2V option is software-selected and therefore there is no need for hardware modifications to output 0-2 volts DC.

The meter now automatically returns to the “Analog Output” prompt. Either press

[ESC] until you exit the User

Program or proceed to the appropriate section to continue setting up the analog output.

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Chapter 4. Setup and Calibration

4.9.2 Setting the Zero Setpoint

Enter the analog output setup menu and proceed as follows:

User Aout Use the [ Aout Type

Zero Setpoint

select press

] and [] keys to

[Zero Setpoint], and

[ENTER]

Span Setpoint

POWER ESC ENTER

Note: The

[Test], [Zero Trim] and [Span Trim] options are also available in the above list box.

At the next prompt, enter the desired zero setpoint.

User Aout Zero-Set Use [] and [] to position the

0000.00 p

POWER ESC ENTER

The meter now automatically returns to the “Analog Output” prompt. Either press

cursor under the desired character. Then, use [ [

] to increment the value.

Press

[ENTER] when done.

] and

[ESC] until you exit the User

Program or proceed to the appropriate section to continue setting up the analog output.

50 CGA 351 User’s Manual

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4.9.3 Setting the Span Setpoint

Enter the analog output setup menu and proceed as follows:

Chapter 4. Setup and Calibration

User Aout Use the [ Zero Setpoint

Span Setpoint

select press

] and [] keys to

[Span Setpoint], and

[ENTER].

Test

POWER ESC ENTER

Note: The

[Test], [Zero Trim] and [Span Trim] options are also available in the above list box.

At the next prompt, enter the desired span setpoint.

User Aout Span-Set Use [] and [] to position the

0000.00 p

POWER ESC ENTER

The meter now automatically returns to the “Analog Output” prompt. Either press

cursor under the desired character. Then, use [ [

] to increment the value.

Press

[ENTER] when done.

] and

[ESC] until you exit the User

Program or proceed to the appropriate section to continue setting up the analog output.

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Chapter 4. Setup and Calibration

4.9.4 Testing the Analog Output

Enter the analog output setup menu and proceed as follows:

User Aout Use the [ Span Setpoint

Test

select

[ENTER].

] and [] keys to

[Test], and press

Zero Trim

POWER ESC ENTER

Note: The

[Aout Type], [Zero Trim] and [Span Trim] options are also available in the above list box.

At the next prompt, enter the desired test percent value, which is the analog output value (expressed as a percentage of the analog output span) used by the meter as a test signal.

User Aout Aout-Test

Test Percent



Use [] and [] to position the cursor. Then, use [

] and []

to increment the test percent to the desired value.

Enter the desired test percent at the above prompt to verify that the analog output device is accurately recording the specified test values. When done, press

[ENTER].

IMPORTANT: The edit box above must be exited (by pressing [ENTER] while in edit mode) and r e-entered for the analog

output device to drive the previously entered value. Entering the span or zero trim spin boxes will also output the entered test percent.

The meter now automatically returns to the “Analog Output” prompt. Either press

[ESC] until you exit the User

Program or proceed to the appropriate section to continue setting up the analog output.

52 CGA 351 User’s Manual

Page 63

4.9.5 Setting the Zero Trim

Using the procedure in “Testing the Analog Output” on page 52, set the Test Percent to 0.

At the analog output setup menu, proceed as follows:

Chapter 4. Setup and Calibration

User Aout Use the [

select

Test

Zero Trim

[Zero Trim], and press

[ENTER].

Span Trim

POWER ESC ENTER

Note: The

[Aout Type], [Zero Setpoint] and [Span Trim] options are also available in the above list box.

At the next prompt, enter the desired value for the zero trim.

User Aout Zero-Trim Use [] and [] to increment

Zero Trim

the value. Press when done.

0 q

POWER ESC ENTER

The meter now automatically returns to the “Analog Output” prompt.

] and [] keys to

[ENTER]

Using the procedure in “Testing the Analog Output” on page 52, reset the Test Percent to its normal value.

Either press

[ESC] until you exit the User Program or proceed to the appropriate section to continue setting up the

analog output.

CGA 351 User’s Manual 53

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Chapter 4. Setup and Calibration

4.9.6 Setting the Span Trim

Using the procedure in “Testing the Analog Output” on page 52, set the Test Percent to 100.

At the analog output setup menu, proceed as follows:

User Aout Use the [ Test Zero Trim

select

[ENTER].

Span Trim

POWER ESC ENTER

Note: The

[Aout Type], [Zero Setpoint] and [Span Setpoint] options are also available in the above list box.

At the next prompt, enter the desired value for the span trim.

User Aout Span-Trim Use [] and [] to increment

Span Trim

the value. Press when done.

0 q

POWER ESC ENTER

The meter now automatically returns to the “Analog Output” prompt.

] and [] keys to

[Span Trim], and press

[ENTER]

Using the procedure in “Testing the Analog Output” on page 52, reset the Test Percent to its normal value.

Either press

[ESC] until you exit the User Program or proceed to the appropriate section to continue setting up the

analog output.

54 CGA 351 User’s Manual

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4.10 Adjusting the Display Contrast

To adjust the contrast of the LCD display, enter the User Program and proceed as follows:

Opt

Cfg Cal

POWER ESC ENTER

Disp Use the [] and [] keys to

select

[Opt] and press

[ENTER].

Chapter 4. Setup and Calibration

Note: The

Cfg Cal

User

Setup

Opt

Disp A list of the available options

is shown. Use the [ keys to select

[ENTER].

[User] and press

] and []

Lock Menus

POWER ESC ENTER

[Lock All] and [Versions] options are also available in the above list box.

Cfg Cal

Analog Output

Contrast

Opt

Disp A list of the available options

is shown. Use the [ keys to select press

[ENTER].

[Contrast] and

] and []

Backlight

POWER ESC ENTER

[Backlight] and [Comm] options are also available in the above list box.

User Adjust-Contrast Use the [] and [] keys to

Adjust Contrast

0 q

POWER ESC ENTER

increment the value to a number between 35 (min. contrast) and 50 (max. contrast). When done, press

[ENTER].

The meter now automatically returns to the “User” prompt. This completes the adjusting of the display contrast. Eit her

[ESC] until you exit the User Program or proceed to the appropriate section of this chapter to continue

press programming the analyzer.

CGA 351 User’s Manual 55

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Chapter 4. Setup and Calibration

4.11 Setting the Display Backlight

To set the LCD display backlight, enter the User Program and proceed as follows:

Note: The

Cfg Cal

User

Setup

Opt

Disp Use the [] and [] keys to

select

[Opt]. Then, Use the []

and [

] keys to select [User]

and press

[ENTER].

Lock Menus

POWER ESC ENTER

[Lock All] and [Versions] options are also available in the above list box.

User Use the [] and [] keys to

select

Contrast

Backlight

[Backlight] and press

[ENTER].

Comm

POWER ESC ENTER

[Fault Alarm] and [Comm] options are also available in the above list box.

User Backlight Use the [] and [] keys to Off On

select the desired option and press

[ENTER].

Timed

POWER ESC ENTER

Note: If

[Off] or [On] was selected, the following prompt does not appear. If [Timed] was selected, enter a value below

for the length of time without keypad activity that the backlight will be turned “Off” until further keypad activity is detected.

User Backlight Timed Use [] and [] to position the

Minutes

POWER ESC ENTER

This completes the adjusting of the display backlight. Either press

cursor under each character. Use [

] and [] to increment

the value of each so the total number is between 00 and 99. When done, press

[ESC] until you exit the User Program or continue

[ENTER].

programming.

56 CGA 351 User’s Manual

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4.12 Setting Up the Serial Port

To set up the serial port, enter the User Program and proceed as follows:

Chapter 4. Setup and Calibration

Cfg Cal

User

Setup

Opt

Disp Use the [] and [] keys to

select

[Opt]. Then, Use the []

and [

] keys to select [User]

and press

[ENTER].

Lock Menus

POWER ESC ENTER

Note: The

[Lock All] and [Versions] options are also available.

User Use the [] and [] keys to

select

Contrast Backlight

[Comm] and press

[ENTER].

Comm

POWER ESC ENTER

Note: The

[Analog Output] options are

[Fault Alarm] and

also available in this list box.

4.12.1 Entering the Node ID

At the following prompt, choose one of the following numbers as the Node ID: 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, or 240.

User Comm Node-ID Use the [] and [] keys to

Node ID

16 q

POWER ESC ENTER

CGA 351 User’s Manual 57

scroll the list of available node ID numbers. When the desired number is highlighted, press

[ENTER].

Page 68

Chapter 4. Setup and Calibration

4.12.2 Entering the Baud Rate

At the following prompt, choose one of the following values as the serial port baud rate: 300, 1200, 2400, 9600, 19200, 38400, 57600, or 115200.

User Comm . . Baud-Rate Use the [

300

1200

scroll the list of available baud rates. When the desired rate is highlighted, press

] and [] keys to

2400

POWER ESC ENTER

4.12.3 Entering the Number of Data Bits

At the following prompt, enter the number of data bits in each data string.

Node I..Data-Length Use the [] and [] keys to

POWER ESC ENTER

select the desired data length and press

4.12.4 Entering the Parity

At the following prompt, enter the parity setting.

[ENTER].

User Comm . . Parity Use the [] and [] keys to

None

Odd

select the parity setting and press

[ENTER].

Even

POWER ESC ENTER

4.12.5 Entering the Number of Stop Bits

At the following prompt, enter the number of stop bits in each data string.

Node-ID..Stop-Bits Use the [] and [] keys to

POWER ESC ENTER

select desired number of stop bits and press

[ENTER].

58 CGA 351 User’s Manual

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4.12.6 Selecting the Type of Serial Port

At the following prompt, enter the type of serial port desired.

Chapter 4. Setup and Calibration

User Comm . . Comm-Type Use the [

RS-232

RS-485

POWER ESC ENTER

select type of serial port and press

] and [] keys to

[ENTER].

The meter now automatically returns to the “Node-ID..Stop-Bits” prompt. This completes the setting of the serial port. Either press

[ESC] until you exit the User Program or proceed to the appropriate section of this chapter to continue

programming the meter.

IMPORTANT: Check to make sure the communication parameters selected match the settings on the computer.

4.13 Setup and Security Settings

After entering the User Program, access the [Opt] submenu to perform the following operations:

• Setting up the option card slots

• Setting the security levels

Proceed to the appropriate section for specific instructions on the topic of interest.

4.13.1 Setting Up the Option Card Slots

To set up the option card slots, enter the User Program and proceed as follows:

Opt

Disp Use the [] and [] keys to

select

[Opt] and press

[ENTER].

Opt

Disp Use the [] and [] keys to

select

[Setup] and press

[ENTER].

Note: The

Cfg Cal

POWER ESC ENTER

Cfg Cal

User

Setup

Lock Menus

POWER ESC ENTER

[Lock All] and [Versions] options also appear in the above list box.

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Chapter 4. Setup and Calibration

4.13.1 Setting Up the Option Card Slots (cont.)

CAUTION! Be careful when using Erase Slot or Erase Main to make sure the information is no longer

needed.

At the following prompt, an option card may be added or removed in an expansion slot, or options may be added or removed in the main (slot 0) position.

Note: The

Setup Use the [

Load Slot

Load Main

select the desired action and press

[ENTER].

Erase Slot

POWER ESC ENTER

[Erase Main] option is also available in the above list box.

Setup Load-Slot Use the [] and [] keys to

1: Load

2: Load

POWER ESC ENTER

select the desired slot designation and press

[ENTER].

ID: Using a personal computer, Size: Received Block:

enter the appropriate information.

] and [] keys to

Write to Slot 1

POWER ESC ENTER

This completes the setting up of the option card slot. To exit the User Program, disconnect and reconnect power to system. Follow the same procedure to add or remove additional option cards.

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4.13.2 Setting the Security Levels

To set up the menu security levels, enter the User Program and proceed as follows:

Opt

Cfg Cal

POWER ESC ENTER

Disp Use the [] and [] keys to

select

[Opt] and press

[ENTER].

Chapter 4. Setup and Calibration

Cfg Cal

Lock Menus

Lock All

Opt

Disp Use the [] and [] keys to

select the desired option and press

[ENTER].

Versions

POWER ESC ENTER

Note: The

[User] and [Setup] options also appear in the above list box.

Because these menus are intended for factory use only, specific programming instructions are not presented here. However, the general purposes of these menus are as follows:

• Lock Menus: this option permits the setting of the security level for any of the individual submenus.

• Lock All: this option institutes password protection for all submenus simultaneously.

• Versions: this option displays the software versions for each of the system components.

After responding to any of the above options, the meter now automatically returns to the “Opt” prompt. This completes the setting of the option slots and the security levels. Either press the appropriate section of this chapter to continue programming the meter.

[ESC] until you exit the User Program or proceed to

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Chapter 4. Setup and Calibration

4.14 Calibrating the CGA 351

To calibrate the CGA 351 analyzer, the following steps must be completed:

• introduce the chosen calibration gas

• regulate the calibration gas flow rate

• adjust the calibration setting as required

Proceed with the instructions in this section to calibrate the analyzer.

4.14.1 Recommended Calibration Gas

To properly calibrate the zirconium oxide oxygen sensor, a calibration gas of known composition must be used. The following calibration gas is recommended by GE:

• 5 ppm O

IMPORTANT: The gas cylinder must be certified as to the exact composition of the calibration gas.

A calibration gas containing only CO is not recommended, since the analyzer will not respond correctly to dry calibration gases that do not contain H

a saturator or bubbler.

Uncertainty in the oxygen content of the calibration gas may be a significant source of error in the calibration process. A standard certificate of analysis has an uncertainty in the smaller component of ±5%. For the recommended calibration gas, this means an oxygen range of 4.5–5.5 ppm, and the corresponding potential calibration errors shown in Table 4 below are introduced.

As shown in Table 4 above, a calibration uncertainty of about ±0.95% is introduced by the calibr ation gas un certainty alone.

in N

. However, CO may be used if moisture is added to the gas by passing it through

Table 4: Calibration Errors

ppm O

4.5 700 225.317 +2.209 +0.99

5.0 223.108 0.00 0.00

5.5 221.110 –1.03 –0.90

T(°C) mV ∆mV %Error

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Chapter 4. Setup and Calibration

4.14.2 Regulating the Calibration Gas Flow Rate

A temporary connection may be made for calibration purposes. However, if a permanent connection is preferred, it should be as short as possible with an isolation valve right at the calibration gas inlet on the analyzer. See the typical sample system in Figure 3 on page 3 for an acceptable arrangement.

Each CGA 351 is tagged with its optimum calibration gas flow rate, based on the testing performed during its factory calibration. Typically, this value will be 400 ± 40 cc/min.

To set up for calibration complete the following steps:

1. Begin the flow of calibration gas to the inlet port of the analyzer, at atmospheric pressure.

2. Using the flowmeter and needle valve supplied with the analyzer, set the calibration gas flow rate to the tagged

value.

3. Set the digital display to show the oxygen concentration in ppm (see “Configuring the Digital Display” on

page 17). At the standard operating temperature of 700°C, an oxygen level of 5 ppm corresponds to a raw sensor

output of 223.108 mV.

Note: Air calibration at 20.9% O

/ 0.0 mV is performed during the factory setup. Field recalibration of this zero mV

point is seldom required.

Note: For other temperatur e and/or oxygen values see Appendix A, The Nernst Equation, for the expected mV output

reading.

If the analyzer does not respond correc tly at th e ta gg ed ca libration gas flow rate (i.e. the oxygen concentration reading is more than 5% in error), the problem is probably due to improper siting of the unit. Contact GE for assistance.

CAUTION!

Make sure the calibration gas flow rate does not exceed 1,200 cc/min (2.5 SCFH). Higher flow rates may cool the oxygen sensor below the normal operating temperature and affect the accuracy of measurements or even cause damage to the oxygen sensor.

The oxygen concentration reading in ppm should correspond to the certified oxygen content of the calibration gas ±5%. If the correct ppm reading is not obtained with the calibration gas, proceed to the next section to adjust the calibration setting.

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Chapter 4. Setup and Calibration

4.14.3 Adjusting the Calibration Setting

After the calibration gas flow to the CGA 351 has been established, as described in the previous sections, the calibration gas setting may be adjusted as necessary. To adjust the heater setting, complete the following steps:

1. Verify that the calibration gas flowing through the analyzer meets the requ irements for oxygen content (5 ppm), flow rate (400 ± 40 cc/min) and pressure (1 Atm).

2. Make sure that the digital display is configured to read the oxygen concentration in ppm.

Note: The oxygen sensor calibration is actually accomplished by adjusting its operating temperature until the

required mV output is achieved.

3. Adjust the heater setting as follows:

1 Oxygen Press

5.05 ppm

POWER ESC ENTER

Note: While in the User Program, press

Cfg

Cal

Opt Disp Use the [] and [] keys to

Cal

Opt Disp A list of the slots available for

Cfg

POWER ESC ENTER

1: Cal

2: Cal

[ESC] to access the User

Program. (The value shown

indicates a +1.0% calibration error.)

[ESC] at any time to abort the current operation.

select

[Cal] and press

[ENTER].

calibration is shown. Use the [

] and [] keys to select

[1: Cal] and press [ENTER].

POWER ESC ENTER

Setup

Cal

Diag Use the [] and [] keys to

select

[Cal] and press

[ENTER].

Slct Cal Menu Item

POWER ESC ENTER

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4.14.3 Adjusting the Calibration Setting (cont.)

Chapter 4. Setup and Calibration

Setup

Heater

POWER ESC ENTER

Cal

Diag Use the [] and [] keys to

select

[Heater] and press

[ENTER].

PPM-Percent Use the [] and [] keys to

select

PPM

Percent

POWER ESC ENTER

[PPM] and press

[ENTER].

At the next prompt, enter the correct value for the oxygen concentration in ppm. Refer to Appendix A, The Nernst Equation, to determine the corresponding sensor output in mV.

PPM-Percent PPM Using the [] and [] keys,

PPM

000.00 p

POWER ESC ENTER

position the cursor under the desired character. Then, use the [

] and [] keys to

increment the value. When done, press

[ENTER].

PPM.. Invalid Output Use the [] and [] keys to

select

Modifying value may cause invalid output

Yes

POWER ESC ENTER

[Yes] and press

[ENTER].

PPM-Percent..Cal-Gas When ready, use the [] and

[

Start the Calibration Gas Back

POWER ESC ENTER

CGA 351 User’s Manual 65

Next Cancel

] keys to select [Next] and

press

[ENTER].

Page 76

Chapter 4. Setup and Calibration

4.14.3 Adjusting the Calibration Setting (cont.)

PPM-Per..Cal-Heater This message appears until the Calibrating Heater S=xxx T=xxx.x D=xx.x

Bac k

POWER ESC ENTER

Calibrating Complete Select Finish Back

POWER ESC ENTER

Cancel

Finish

calibration adjustment has been completed (usually about 15–30 minutes).

If the calibration passed, use the [

] and [] keys to select

[Finish] and press [ENTER].

1 Oxygen The value shown is now the

5.00 ppm

correct ppm value for the oxygen content of the calibration gas.

POWER ESC ENTER

Note: If the calibration “Failed”, repeat the calibration procedure. If another failure occurs, contact GE for

assistance.

4. Discontinue the flow of calibration gas to the analyzer.

5. Resume the flow of process gas to the analyzer.

6. If necessary, reconfigure the digital display to show the desired process parameter.

The CGA 351 may now be placed back into service.

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Chapter 4. Setup and Calibration

4.15 Checking the Current Settings

To aid in monitoring the operation of the CGA 351, a built-in diagnostics routine is included in the User Program. To access this submenu, proceed as follows:

1 Oxygen Press

2.71 ppm

POWER ESC ENTER

Note: While in the User Program, press

Cfg

Cal

Opt Disp Use the [] and [] keys to

Slct Cal Menu Item

POWER ESC ENTER

Cfg

Cal

Opt Disp A list of the slots available for

1: Cal

2: Cal

[ESC] to access the User

Program.

[ESC] at any time to abort the current operation.

select

[Cal] and press

[ENTER].

calibration is shown. Use the [

] and [] keys to select

[1: Cal] and press [ENTER].

POWER ESC ENTER

Setup Cal

Diag

Use the [] and [] keys to select

[Diag] and press

[ENTER].

Slct Cal Menu Item

POWER ESC ENTER

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Chapter 4. Setup and Calibration

4.15.1 Checking the Sensor Impedance

Enter the [Diag] menu as described on page 67, and proceed as follows:

Setup Cal

Impedance

Vi ew Temp C ontrols

POWER ESC ENTER

Diag

Use the [] and [] keys to select

[Impedance] and press

[ENTER].

Sensor-Impedance The oxygen sensor impedance, Impedance xxx.xx

POWER ESC ENTER

in ohms, is shown. Press

[ENTER] to continue.

The meter now automatically returns to the “1:Cal” prompt. This completes the checking of the sensor impedance. Either press

[ESC] until you exit the User Program or proceed to the next section of this chapter to continue checking

the settings.

4.15.2 Viewing the Heater Settings

Enter the [Diag] menu as described on page 67, and proceed as follows:

Setup Cal

Impedance

View Temp Controls

POWER ESC ENTER

Diag

Use the [] and [] keys to select

[View Temp Controls]

and press

[ENTER].

View Temp Controls The current temperature SetP Prop IntT Duty xxx xxxx xxxx xxx

POWER ESC ENTER

control settings are shown. Press

[ENTER] to continue.

Note: The four values shown are the current setpoint, proportional band, integration time, and maximum duty cycle.

The meter now automatically returns to the “Diag” prompt. This completes the viewing of the heater settings. Press

[ESC] until you exit the User Program.

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Chapter 5. Service and Maintenance

5.1 Introduction

The CGA 351 has been designed to provide years of trouble-free operation. However, because of the technical challenges involved in measuring very low levels of oxygen, some difficulties may occasionally be encountered. The procedures for resolving many of these situations are discussed in this chapter. If the information provided in this chapter is insufficient to solve the problem, please contact the factory for further assistance.

If a faulty component is discovered in the CGA 351, that component is usually replaceable on site. Contact GE to obtain a new part, and proceed to the appropriate section of this chapter for installation instructions.

WARNING!

5.2 General Troubleshooting

This section discusses the following general categories of problems that may arise with the CGA 351:

• Faulty wiring

• A faulty thermocouple

• A faulty oxygen sensor

• A faulty sensor furnace

• Missing sensor furnace voltage

Use this section to troubleshoot any malfunction in the CGA 351. Refer to Figure 10 on page 89, and complete the following sections in the sequence indicated.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

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Chapter 5. Service and Maintenance

5.2.1 Checking the Wiring

Complete the two checks listed below to correct any wiring problems.

WARNING!

Be careful when tightening the terminal block electrical connections. Full line voltage is present on some terminals.

WARNING!: These symbols indicate Caution - dangerously hot surfaces and risk of electric shock, respectively:

1. Open the cover on the sensor enclosure and remove the lower front panel from the electronics enclosure.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

2. Check all wiring, including that performed at the factory. Refer to the wiring instructions in Chapter 2, Installation, and the wiring diagram in Figure 6 on page 14, to make sure that all wires are attached to the correct pins. If any connections are loose, turn the screws clockwise with a small screwdriver to secure the connections.

3. Locate the oxygen sensor clips (see Figure 10 on page 89) and short them together with a jumper. The oxygen display should read 20.93%.

Note: Due to an uncorrected offset in some units, an exact reading of 20.93% may not be obtained. However, the

result should be close to this value.

4. If the wiring is good and a 20.93% oxygen reading is obtained with the shorted clips, remove the jumper, and proceed to the next section.

Note: If an open loop (OL) is measured at the oxygen sensor clips, recheck the wiring and try again. If the OL

reading repeats, contact ge for assistance.

Note: A cold sensor will always indicate an open loop (OL).

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5.2.2 Checking the Thermocouple

To check the thermocouple temperature sensor used in the CGA 351, complete the following steps:

WARNING!

There are very hot surfaces in the sensor enclosure. Touching any of these surfaces without heat resistant gloves will result in serious burns.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

1. Locate the thermocouple (

TB2.

2. Using a digital multimeter, measure the voltage across the

TC) leads on pin + (yellow - no number) and pin - (red - no number) on terminal block

TC terminals. One of the conditions listed in Table 5

below should occur.

Table 5: TC Voltage Reading at 700°C

Voltage Reading Recommended Action

25–31 mV The temperature is good - proceed to the oxygen

sensor check (see page 73).

<25 mV The temperature is low - proceed to the sensor

furnace check (see page 73).

0 mV reading The TC is defective - proceed to the TC

replacement instructions (see page 82).

3. Complete the action recommended in Table 5 above.

Note: If a voltage reading other than those listed above is obtained, refer to Figure 9 on page 72 and/or Table 6 on

page 72 to determine the operating temperature of the sensor furnace. A standard CGA 351 operates at a

temperature of 700°C.

Based on the recommended action in Table 5 above, proceed to the appropriate section for further instructions.

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Chapter 5. Service and Maintenance

500 600 700 800 900 1000 1100 1200

TEMPERATURE (°C)

VOLTAGE (mV)

5.2.2 Checking the Thermocouple (cont.)

Figure 9: TC Voltage vs. Temperature

Table 6: TC Voltage vs. Temperature

Temp.( °C) E(

mV)

Temp.(°C) E(

20 (0.7981) 730 29.5841 500 19.8462 740 30.0002 550 21.9783 750 30.4153 600 24.1073 760 30.8296 610 24.5322 770 31.2429 620 24.9566 780 31.6553 630 25.3805 790 32.0668 640 25.8039 800 32.4773 650 26.2267 850 34.5150 660 26.6489 900 36.5278 670 27.0705 950 38.5154 680 27.4914 1000 40.4775 690 27.9115 1050 42.4131 700 28.3309 1100 44.3206 710 28.7494 1150 46.1973 720 29.1672 1200 48.0401

mV)

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Chapter 5. Service and Maintenance

5.2.3 Checking the Oxygen Sensor

If the thermocouple voltage was within the normal range, the troubleshooting sequence should continue here.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

1. Disconnect the oxygen sensor (

O2) leads (white +, -) from terminal block TB2.

2. Using a digital multimeter, measure the resistance between the two disconnected oxygen sensor leads.

3. If the measurement indicates an open loop (OL), adjust the clips to make certain they are making good contact with

the oxygen sensor and take another reading. If an open loop is still measured, the oxygen sensor is defective and must be replaced.

Note: A cold sensor will always indicate an open loop (OL).

If the oxygen sensor tests good, proceed to the next section to continue the troubleshooting procedure.

5.2.4 Checking the Sensor Furnace

If the sensor furnace operating temperature was too low, the troubleshooting sequence should resume here.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

1. Disconnect the sensor furnace (

2. Using a digital multimeter, measure the resistance across the disconnected sensor furnace leads. One of the

conditions listed in Table 7 below should occur.

Resistance Reading Recommended Action

approximately 66 ohms The sensor furnace is good - check the furnace

open loop (OL) The sensor furnace is bad - replace the sensor

HEATER) leads (white 1, 2) from terminal block TB2.

Table 7: Sensor Furnace Resistance Reading

voltage input (see page 74).

furnace (see page 83).

Note: The sensor furnace impedance may also be checked in the User Program. Proceed to the

Diag>Impedance

prompt, as described on page 68 (also, see Figure 8 on page 25), and display the current value.

3. If the sensor furnace is good, reconnect the sensor furnace leads to terminal block

TB2.

Based on the recommended action in Table 7 above, proceed to the appropriate section for further instructions.

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Chapter 5. Service and Maintenance

5.2.5 Checking the Sensor Furnace Voltage

If the sensor furnace impedance test indicated that the sensor furnace is good, continue the troubleshooting procedure here.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

1. Using a digital multimeter, measure the sensor furnace AC input voltage on terminal block

page 14 for the location of

approximately full line voltage

no voltage present There is no power reaching the sensor furnace -

2. Remove the terminal board fuse (see Figure 6 on page 14) and check it for continuity. If the fuse is blown, replace

it with a new fuse of the same size and type listed in Chapter 6, Specifications.

3. If the fuse was good, the main voltage supply is bad. Check the external disconnect device and/or the main voltage

source to that device.

Based on the recommended action in Table 8 above, proceed to the appropriate section for instructions. If the problem has still not been resolved at this point, contact the factory for assistance.

TB2 and the HEATER pins. One of the conditions listed in Table 8 below should occur.

Table 8: Furnace Voltage Reading

Voltage Reading Recommended Action

Defective digital display unit - replace the digital display (see page 85).

proceed with the next step.

TB2. See Figure 6 on

5.3 Oxygen Measurement Errors

This section discusses each of the following possible oxygen errors:

• Oxygen concentration stuck at 20.93%

• Oxygen concentration reading above 100%

• Oxygen reading too low

• Oxygen reading too high

Refer to the appropriate section of this chapter and to Figure 10 on page 89 for help in troubleshooting each of the above situations.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

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Chapter 5. Service and Maintenance

5.3.1 Oxygen Concentration Reads Constant 20.93%

This condition is unusual and is likely to be caused either by a short in the oxygen sensor wiring, a severe air leak in the plumbing or a defective digital display. A brief description of how to remedy this problem is presented below.

WARNING!

WARNING!: This symbol indicates Caution - dangerously hot surfaces:

The sensor enclosure is hot. Use heat-resistant gloves when handling the enclosure.

5.3.1a Checking the Oxygen Sensor Wiring

Refer to Figure 10 on page 89 for the location of the oxygen sensor clips, and check for a short circuit in the contact clip wiring (two wires touching). If this does not correct the problem, proceed to the next section.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

5.3.1b Checking for Plumbing Leaks

A plumbing leak permits cross-contamination of the reference air and the sample gas. Use the following steps to remedy the problem:

1. Make sure that the calibration gas port in the sample system has not been left open. This would admit atmospheric

air into the sample system and force a 20.93% reading.

2. Open the sensor enclosure cover and check all plumbing connections for leaks. Make sure that the oxygen sensor

nut and the inlet connections are properly sealed.

When the reference air is contaminated by the same gases that are being measured, the oxygen sensor generates a 0.00 mV analog output signal and a 20.93% oxygen reading. Opening the cover permits uncontaminated reference air to enter the unit. If opening the cover and fixing any plumbing leaks does not cause the 20.93% reading to drop, proceed to the next section.

3. If the oxygen reading drops in Step 2 above, tighten all fittings by 1/8 turn and close the sensor enclosure cover . If

the oxygen reading gradually returns to 20.93%, try tightening the fittings an additional 1/8 turn. If the problem persists, contact GE for assistance.

CAUTION!

Do not tighten fittings more than 1/8 turn at a time.

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Chapter 5. Service and Maintenance

5.3.1c Checking the Digital Display

If the shorted wiring and plumbing leak checks have not corrected the problem, complete the following steps:

1. Disconnect the oxygen sensor (

2. Connect the positive lead of a digital voltmeter to the wire (white - #1) removed from pin

negative voltmeter lead to the wire (white - #2) removed from pin

IMPORTANT: The oxygen sensor leads must be removed from the terminal block for this test. If the leads are not

disconnected, a short on the digital display circuit board could result in a false 0.00 mV reading.

3. A voltage reading of 0.00 mV should be obtained, to correspond with the 20.93% oxygen reading. If any voltage

other than 0.00 mV is measured, the digital display is defective. Contact GE for assistance.

O2) leads from terminal block TB2.

+ and connect the

5.3.2 Oxygen Reading Above 100%

An oxygen display reading greater than 100% is almost always caused by reversed wiring of the oxygen sensor. For example, 4% oxygen at 700°C would generate an oxygen sensor output of +34.69 mV. However, reversed oxygen

sensor wiring would cause this reading to be –34.69 mV. The Nernst equation calculation would then convert this voltage to an oxygen display of 109.49%!

• T o correct this problem, check the ox ygen sensor wiring at terminal block TB2 for the correct polarity (refer to

Figure 6 on page 14).

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

5.3.3 Oxygen Reading Too Low

This condition is usually caused by combustibles in the sample gas, but it may also be the result of the oxygen sensor being out of calibration. To correct the condition, complete the following steps:

1. The sample gas may be contaminated with combustibles from grease or oil in the plumbing. The oxygen sensor

will cause combustibles such as CO, H oxygen in the sample gas. This will give a reading that may be less than the expected amount of oxygen. To fix the

problem, remove the source of the contamination.

2. If the sample gas is not contaminated with hydrocarbons, recalibrate the oxygen sensor. See

“Calibrating the CGA 351” on page 62, for the correct procedure.

, or hydrocarbons in the sample to react with oxygen, thus depleting the

5.3.4 Oxygen Reading Too High

This condition is most likely caused either by poor quality reference air , a leak in the plumbing or an oxygen sensor that is too cool. A brief description of possible solutions to this problem is presented in the next section.

WARNING!

WARNING!: This symbol indicates Caution - dangerously hot surfaces:

The sensor enclosure is hot. Use heat-resistant gloves when handling the enclosure.

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5.3.4a Check for Plumbing Leaks

A plumbing leak permits contamination of the reference air by the sample gas. The resulting reduction in the ratio of the oxygen partial pressures reduces the mV output from the oxygen sensor and yields a percent oxygen reading that is higher than expected. Use the following steps to remedy the problem:

1. Open the sensor enclosure cover to allow uncontaminated reference air to enter the unit.

2. If the oxygen reading drops in Step 1 above, tighten all fittings by 1/8 turn and close the sensor enclosure cover . If

the oxygen reading gradually increases, repeat Step 1. If the problem persists, proceed to the next section.

CAUTION!

Do not tighten fittings more than 1/8 turn at a time.

5.3.4b Check the Oxygen Sensor Temperature

If the oxygen sensor is below its normal operating temperature, the mV output will be too low and the percent oxygen reading will be higher than expected. Proceed as follows:

• The easiest way to check the sensor temperature is to calibrate the oxygen sensor as described in “Calibrating

the CGA 351” on page 62. The calibration procedure includes instructions for adjusting the sensor furnace

temperature, if necessary.

If the problem has not been resolved by the steps in this section, contact GE for assistance.

5.4 Calibration Responses

Chapter 4, Setup and Calibration, describes the procedures for calibrating the CGA 351 in great detail. However, the response of the unit to the calibration procedures can provide valuable clues to potential problems with the installation. The three most common situations are described in this section.

5.4.1 Everything Is Fine

Calibration of the analyzer at the tagged calibration gas flow rate has been successfully completed. Upon switching off the calibration gas, the analyzer quickly returns to monitoring and displaying the sample gas concentrations accurately. This indicates that proper operating conditions have been achieved and the analyzer can be expected to perform reliably.

5.4.2 Forced Flow Problem

If a flow rate higher than the tagged calibration gas flow rate is required to calibrate the analyzer, the sample gas feed pressure is too high. Under such conditions, the sample is not entering the oxygen sensor by diffusion only, but it is being forced into the sensor instead. In addition to the calibration problem, sensor life may be shortened and analyzer plugging may occur. If forced flow is confirmed as the problem, refer to Chapter 2, Installation, for instructions on proper installation of the analyzer.

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Chapter 5. Service and Maintenance

5.4.3 Plugging or Dead Space Problem

The analyzer was successfully calibrated at the tagged calibration gas flow rate, and the analyzer responded quickly to the calibration gas. However, there is a significant delay in reading the correct sample gas concentrations, after turning off the calibration gas.

When this problem occurs, it is very likely that the sample gas inlet is located in a dead space. After the analyzer is correctly reading the sample gas concentration, switch on the calibration gas just long enough to get the correct reading. As soon as the analyzer reads the correct value, quickly shut off the calibration gas. One of two responses should occur:

1. If the recovery time is still too long, the sample gas path through the oxygen sensor may be plugged with

particulates. Use of a blowback system (contact GE for assistance) should clear the analyz er and restore proper operation.

2. If the analyzer reading recovers promptly, dead space is the likely problem. Internal structures can cause dead

spaces that are not evident from an external examination. It may sometimes be necessary to relocate the analyzer to a more suitable installation site.

Note: If the calibration “Failed”, repeat the calibration procedure (see “Calibrating the CGA 351” on page 62). If

another failure or any situations not covered in this chapter are encountered, contact GE for assistance.

5.5 Parts Replacement

The CGA 351 is designed to enable easy and quick servicing, if necessary. This section describes the replacement of major and minor components of the analyzer. However, before actually replacing any component, carefully read the complete instructions to become familiar with the procedures.

Each procedure in this section includes a list of the equipment needed to complete the component replacement. Please make sure that any necessary replacement parts are on hand before dismantling the analyzer. In addition, the first paragraph of each section gives a description of the function and location of the part to be replaced. refer to Figure 10 on page 89, while following the step-by-step instructions in this section.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

CAUTION!

If service procedures not covered in this chapter become necessary, please contact GE for assistance.

WARNING!

If the power must be disconnected to replace a part, perform the replacement as quickly as possible. The CGA 351 is susceptible to corrosion from acid condensation if it remains without power for more than thirty minutes.

WARNING!: These symbols indicate Caution - dangerously hot surfaces and risk of electric shock, respectively:

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5.5.1 The Sensor Enclosure

Those components associated with the oxygen measurement process are located in the sensor enclosure. This section describes the proper procedures for replacing these parts.

WARNING!

WARNING!: These symbols indicate Caution - dangerously hot surfaces and risk of electric shock, respectively:

CAUTION!

Proceed to the appropriate section to replace the desired component.

There are extremely hot surfaces in the sensor enclosure. If these surfaces are touched, serious burns could result. Always wear heat-resistant gloves while performing these procedures.

Rapid cooling of the oxygen sensor will result in cracks in the ceramic that will render the sensor unusable. Before opening the door to the sensor enclosure, allow about two hours after the system is powered down for the sensor to cool slowly.

5.5.1a Replacing the Oxygen Sensor Clips

The oxygen sensor is connected to the electronics via two contact clips located at the base of the sensor. The upper clip is electrically isolated from the lower clip by a non-conductive band on the sensor body . Both clips simply snap around the body of the sensor .

The following tools are needed to replace the oxygen sensor clips:

• Pliers

• Wire cutters

• Wire strippers

• Crimping tool

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5.5.1a Replacing the Oxygen Sensor Clips (cont.)

Power may remain on while completing the following steps:

1. Open the sensor enclosure cover.

2. Locate the oxygen sensor and the oxygen sensor clips (see Figure 10 on page 89).

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

IMPORTANT: Never touch the coating on the oxygen sensor with bare hands.

3. Use pliers to remove the upper and lower clips from the oxygen sensor. The clips are easily removed by pulling

them away from the oxygen sensor body.

4. Cut off the old upper clip, leaving the remaining wire as long as possible.

5. Strip 1/2” of insulation off the upper clip wire, and slide the new upper clip over the stripped wire. Using a

crimping tool, crimp the new upper clip onto the upper clip wire.

6. Repeat steps 4 and 5 to install the new lower clip.

7. Reinstall both clips onto the oxygen sensor body.

8. Close the cover on the sensor enclosure.

9. Recalibrate the oxygen sensor as described in “Calibrating the CGA 351” on page 62.

This completes the replacement of the oxygen sensor clips.

5.5.1b Replacing the Oxygen Sensor Assembly

IMPORTANT: For proper operation in the low ranges, the oxygen sensor assembly must be replaced as a unit. Never

attempt to replace just the oxygen sensor itself.

The oxygen sensor assembly is mounted beneath the sensor furnace and is readily accessible for quick and easy replacement. The following items are needed to replace the oxygen sensor:

• Adjustable wrench

• Screwdriver

• Pliers

CAUTION!

WARNING!: These symbols indicate Caution - dangerously hot surfaces and risk of electric shock, respectively:

When replacing the oxygen sensor assembly, do not touch the new oxygen sensor with bare hands. Handle the assembly by the mounting plate and/or manifold.

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5.5.1b Replacing the Oxygen Sensor Assembly (cont.)

WARNING! There are extremely hot surfaces in the analyzer. Touching these surfaces will result in serious

burns. Use heat-resistant gloves while replacing the oxygen sensor.

To remove the defective oxygen sensor assembly, proceed as follows:

1. Remove the inlet and outlet process connections, and open the sensor enclosure cover.

2. Locate the oxygen sensor and the oxygen sensor clips (see Figure 10 on page 89). Use pliers to remove the upper

and lower clips from the oxygen sensor. The clips are easily removed by pulling them away from the oxygen sensor body.

3. Remove the four screws that secure the sensor/manifold mounting plate to the bottom of the sensor enclosure.

Make sure that the sensor does not hit the sides of the sensor furnace, and carefully slide the sensor assembly out of the enclosure.

IMPORTANT: Note the orientation of the mounting plate and the manifold while removing the assembly.

CAUTION!

When replacing the oxygen sensor assembly, do not touch the new oxygen sensor with bare hands. Handle the assembly by the mounting plate and/or manifold.

To install the new oxygen sensor, complete the following steps:

1. Insert the sensor/manifold assembly through the opening in the bottom of the sensor enclosure and into the sensor

furnace. Make sure that the assembly is oriented in the same way as the old assembly.

CAUTION!

If the sensor furnace is hot, insert the new oxygen sensor slowly. Take 45-60 seconds to fully insert the sensor into the furnace. If the sensor is inserted too quickly, it will crack.

2. Secure the mounting plate to the bottom of the enclosure with the four screws previously removed.

3. Reinstall the upper and lower clips onto the oxygen sensor body.

4. Connect the inlet and outlet process fittings to the bottom of the sensor enclosure.

5. Close the cover on the sensor enclosure.

6. Calibrate the new oxygen sensor as described in “Calibrating the CGA 351” on page 62.

This completes the replacement of the oxygen sensor assembly.

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5.5.1c Replacing the Thermocouple

The thermocouple is mounted on the bottom of the sensor furnace and extends approximately 2–3 in. into the sensor furnace.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

CAUTION!

To prevent damage, the oxygen sensor must cool for about two hours after the unit is powered down before the sensor enclosure door may be opened. Then, replace the thermocouple and reconnect the power as quickly as possible to prevent corrosion of the analyzer components due to acid condensation.

WARNING!: These symbols indicate Caution - dangerously hot surfaces and risk of electric shock, respectively:

A standard screwdriver is the only tool needed for replacement of the thermocouple. Complete the following steps, in the order shown, to remove the defective thermocouple:

1. Disconnect the main power to the CGA 351.

WARNING!

Failure to disconnect the main power at the external disconnect device before proceeding will result in serious personal injury.

2. Open the cover on the sensor and electronics enclosures.

WARNING!

The sensor furnace may still be hot. Always use heat-resistant gloves when handling it.

3. Remove the oxygen sensor/manifold assembly, as described in the previous section.

4. Disconnect the thermocouple leads from

TB2 in the electronics enclosure (make a note of the terminal pins for each

lead), and pull the leads through the conduit and into the sensor enclosure.

5. Remove the screw that secures the integral thermocouple clamp to the bottom of the sensor furnace.

6. Extract the thermocouple from the sensor furnace, through the opening in the bottom of the sensor enclosure.

Install the new thermocouple by completing the following steps:

1. Insert the new thermocouple into the sensor furnace, being careful not to strike it against the heating element or the

pipe wall inside the sensor furnace.

2. Secure the thermocouple clamp to the bottom of the sensor furnace with the screw previously removed.

3. Route the thermocouple wires through the conduit and into the electronics enclosure.

4. Connect the thermocouple wire leads to the same pins from which the old leads were removed. The positive

(yellow) and negative (red) leads must be connected with the correct polarity.

5. Reinstall the oxygen sensor/manifold assembly into the bottom of the sensor enclosure and install the upper and

lower oxygen sensor clips, as described in the previous section.

6. Close the covers on both enclosures. This completes the replacement of the thermocouple.

7. Energize the main power to the meter and calibrate the oxygen sensor (see “Calibrating the CGA 351” on

page 62).

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5.5.1d Replacing the Sensor Furnace

The sensor furnace, which maintains the oxygen sensor at a stable operating temperature, is located in the sensor enclosure and is easily replaceable. The following tools are required:

• screwdriver

• digital multimeter

CAUTION!

WARNING!: These symbols indicate Caution - dangerously hot surfaces and risk of electric shock, respectively:

Complete the following steps, in the order given, to remove the old sensor furnace:

1. Disconnect the main power to the CGA 351.

WARNING!

2. Open the cover on the sensor enclosure.

WARNING!

3. Remove the oxygen sensor/manifold assembly and the thermocouple, as described in the previous sections.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

4. Free the sensor furnace from its mounting bracket by removing the two screws on the top and bottom of the

furnace, and lift the sensor furnace out of the enclosure.

To replace the sensor furnace, the power to the CGA 351 must be disconnected. Therefore, replace the sensor furnace and reconnect the power as quickly as possible to prevent corrosion of the analyzer components due to acid condensation.

Failure to cut the main power at the external disconnect device before proceeding will result in serious personal injury.

The sensor furnace may still be hot. Always use heat-resistant gloves when handling it.

Appendix C.

5. Locate the ceramic block on the bottom of the sensor furnace and loosen the two (2) terminal screws closest to the

outer edge of the sensor furnace.

IMPORTANT: Do not completely remove the terminal screws from the ceramic power block.

6. Carefully remove the two leads from the loosened terminal screws near the outer edge of the sensor furnace.

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5.5.1d Replacing the Sensor Furnace (cont.)

This completes the removal of the old sensor furnace. Install the new sensor furnace immediately, by completing the following instructions:

1. Locate the ceramic block, which is located on the bottom surface of the new sensor furnace.

2. Feed each of the previously removed sensor furnace wires through the outside, then the inside, of the ceramic

block. Reconnect the two wires to the outer terminals on the ceramic block.

3. Make sure the internal power leads are fed all the way through the ceramic block, in order to make a good

connection, and that they exit on the opposite side from which they were inserted. Tighten all four (4) terminal screws on the ceramic block.

4. Using a digital multimeter, check the resistance of the sensor furnace heating element. Specific instructions may be

found on page 73.

5. Reinstall the thermocouple and the oxygen sensor/manifold assembly into the sensor enclosure, as described on

page 81 (starting with step 3).

6. Close the cover on the sensor enclosure. This completes the replacement of the sensor furnace.

7. Reconnect the main power to the unit and recalibrate the oxygen sensor (see “Calibrating the CGA 351” on

page 62).

5.5.2 The Electronics Enclosure

Those components associated with the electronic conditioning of the signals generated by the oxygen measurement components are located in the electronics enclosure. This section describes the proper procedures for replacing these parts.

The user-serviceable parts located in the electronics enclosure (see Figure 6 on page 14) include the following:

• Main power fuse

• Digital panel meter

• Controller card

• Option card(s)

Proceed directly to the appropriate section to replace any of the above components.

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

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5.5.2a Replacing the Fuse

If the main power fuse is defective, install a new fuse by completing the following steps:

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

1. Disconnect the main power to the CGA 351.

WARNING!

Failure to cut the main power at the external disconnect device before proceeding will result in serious personal injury.

2. Remove the cover beneath the digital display panel on the electronics enclosure.

3. Locate the fuse holder (see Figure 6 on page 14) on the lower right side of the terminal board. Remove the old

fuse.

4. Install a new fuse of the same type and rating. See Chapter 6, Specifications, for the correct fuse to use.

5. Install the cover on the electronics enclosure, and reapply power to the analyzer.

The CGA 351 may now be placed back into service.

5.5.2b Replacing the Digital Panel Meter

If the digital panel meter is defective, remove the defective meter by completing the following steps:

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

1. Disconnect the main power to the CGA 351.

WARNING!

2. Remove the four sets of mounting hardware and remove the electronics enclosure from its mounting surface.

Failure to cut the main power at the external disconnect device before proceeding will result in serious personal injury.

3. Remove the eight screws on the rear of the enclosure and lift the mounting plate off the enclosure.

4. Make a sketch of all wiring connections to the rear of the digital panel meter, and then disconnect all the wiring.

5. Remove the two mounting brackets and push the panel meter out through the front of the enclosure. Remove the

controller and option cards from Slots 1 and 2, respectively.

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5.5.2b Replacing the Digital Panel Meter (cont.)

Install the new meter by completing the following steps:

1. Install the original controller and option cards into Slots 1 and 2, respectively, of the new meter.

2. Insert the new meter through the opening in the front of the electronics enclosure and secure it in place with the two

brackets.

3. Reconnect all of the wires to the connectors on the rear of the new digital panel meter.

4. Place the mounting plate over the rear of the electronics enclosure and secure it with the eight screws previously

removed.

5. Mount the electronics enclosure back onto the wall/panel and secure it with the four sets of hardware previously

removed.

6. Reconnect the main power to the analyzer.

7. Refer to Chapter 3, Operation, and Chapter 4, Setup and Calibration, to reprogram the new digital panel meter.

The CGA 351 is now ready to be placed back into service.

Replacing the Controller Card

To replace a defective controller card, complete the following steps:

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

1. Disconnect the main power to the CGA 351.

WARNING!

Failure to cut the main power at the external disconnect device before proceeding will result in serious personal injury.

2. Remove the panel meter, as described in the previous section.

3. Remove the defective controller card from Slot 1 of the panel meter, and install the new controller card in its place.

4. Reinstall the panel meter into the electronics enclosure, as described in the previous section above.

5. Reconnect the main power to the analyzer.

6. Refer to Chapter 3, Operation, and Chapter 4, Setup and Calibration, to reprogram the new digital panel meter.

The CGA 351 is now ready to be placed back into service.

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5.5.2c Replacing the Option Card

To replace a defective option card, complete the following steps:

Note: For information regarding component locations and wiring connections in an optional enclosure, see

Appendix C.

1. Disconnect the main power to the CGA 351.

WARNING!

2. Remove the panel meter, as described in a previous section.

3. Remove the defective option card from Slot 2 of the panel meter, and install the new option card in its place.

4. Reinstall the panel meter into the electronics enclosure, as described in a previous section.

5. Reconnect the main power to the analyzer.

6. Refer to Chapter 3, Operation, and Chapter 4, Setup and Calibration, to reprogram the new digital panel meter.

The CGA 351 is now ready to be placed back into service.

Failure to cut the main power at the external disconnect device before proceeding will result in serious personal injury.

5.6 Recommended Spare Parts

The recommended spare parts for the CGA 351 are listed in Table 9 below:

Table 9: Spare Parts List - CGA 351

Part Number Qty Description

1214-510 2 Outer Oxygen Sensor Clip

238-085 1 Thermocouple (K-Type) Temperature Detector Assembly 705-950 1 Inlet Ceramic Tube Fitting, platinum mesh included 705-952 1 Zirconium Oxide Oxygen Sensor Assembly with manifold 227-007 1 Furnace

183-047 1 LCD Display PCB 703-1304-01 1 Controller Card (256KB SRAM) 703-1320-02 1 Power Supply PCB

703-1350 1 Basic I/O PCB

703-1361-01 1 Quad Alarm PCB (32K EPROM)

703-1376 1 CGA351 Sensor PCB 703-1362 1 CGA351 Interconnect PCB

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View A-A

Sensor Furnace

Mounting Plate

(bottom view)

Outlet Fitting

Inlet Fitting

Mounting Screw

6 pl

Inlet Fitting

Mounting Plate

Manifold

Fitting Nut

Oxygen Sensor

Ceramic Block

Mounting Holes

Thermocouple

Mounting Bracket

Mounting Screw

Sensor Upper Clip

Sensor Lower Clip

Sensor Furnace

(bottom)

Chapter 5. Service and Maintenance

Figure 10: CGA 351 Parts Replacement

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CGA 351 User’s Manual 90

GE Sensing CGA 351 Operating Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Chapter 1. General Information

1.1 Introduction

1.2 The Sensor Enclosure

1.3 The Sample System

1.4 Principles of Operation

1.5 The Zirconium Oxide Oxygen Sensor

1.6 The Heater Control Circuit

Chapter 2. Installation

2.1 Introduction

2.2 Choosing an Installation Site

2.3 Mounting the CGA 351

2.4 Connecting the Sample System

2.5 Wiring the Analyzer

2.5.1 Wiring the Outputs (TB1)

2.5.2 Wiring the Inputs (TB2)

2.5.3 Wiring the Line Power (TB3)

Chapter 3. Operation

3.1 Introduction

3.2 Preventing Common Problems

3.3 Powering Up the System

3.4 User Program Security

3.5 Configuring the Digital Display

3.5.1 Initial Screen Displays

3.5.2 Configuration Options

3.5.3 Using the Auto Range Feature

3.5.4 Configuring the Alarms

3.5.5 Configuring the Analog Output

3.5.6 Switching Display Windows

3.6 Converting mV to Oxygen Concentration

3.7 Powering Down

Chapter 4. Setup and Calibration

4.1 Introduction

4.2 Accessing the User Program

4.3 The [Cal] Menu

4.4 Setting Up the Alarm Relays

4.4.1 Setting the Trip Type

4.4.2 Setting the Trip Value

4.4.3 Setting the Deadband Value

4.4.4 Testing the Alarm Relays

4.4.5 Selecting the Operating Mode

4.5 Setting the Temperature Controls

4.5.1 Entering the Setpoint

4.5.2 Entering the Sensor Temperature

4.5.3 Setting the Air Offset

4.5.4 Selecting the Gas Type

4.5.5 Selecting the Proportional Band

4.5.6 Setting the Integration T ime

4.5.7 Setting the Maximum Duty Cycle

4.5.8 Restoring the Default Values

4.6 Auto Range Analog Output

4.6.1 Factory Defaults

4.6.2 Programming the Auto Ranges

4.7 The [Opt-User] Menu

4.8 Setting Fault Alarm Type

4.9 Setting Up the Analog Output

4.9.1 Selecting the Analog Output Type

4.9.2 Setting the Zero Setpoint

4.9.3 Setting the Span Setpoint

4.9.4 Testing the Analog Output

4.9.5 Setting the Zero Trim

4.9.6 Setting the Span Trim

4.10 Adjusting the Display Contrast

4.11 Setting the Display Backlight

4.12 Setting Up the Serial Port

4.12.1 Entering the Node ID

4.12.2 Entering the Baud Rate

4.12.3 Entering the Number of Data Bits

4.12.4 Entering the Parity

4.12.5 Entering the Number of Stop Bits

4.12.6 Selecting the Type of Serial Port

4.13 Setup and Security Settings

4.13.1 Setting Up the Option Card Slots

4.13.2 Setting the Security Levels

4.14 Calibrating the CGA 351

4.14.1 Recommended Calibration Gas

4.14.2 Regulating the Calibration Gas Flow Rate