Rosemount 755A User manual

Rosemount Analytical
MODEL 755A
OXYGEN ANALYZER
INSTRUCTION MANUAL
245364-U

NOTICE
The information contained in this document is subject to change without notice.
Manual Part Number 245364-U
April 2000
Printed in U.S.A.
Rosemount Analytical Inc.
4125 East La Palma Avenue
Anaheim, California 92807-1802
Teflon® is a registered trademark of E.I. duPont de Nemours and Co., Inc.
SNOOP® is a registered trademark of NUPRO Co.

CONTENTS
245364-U Rosemount Analytical April 2000 i
Model 755A Oxygen Analyzer
PREFACE
INTENDED USE STATEMENT ............................................................................P-1
SAFETY SUMMARY ............................................................................................P-1
SPECIFICATIONS - GENERAL ...........................................................................P-3
SPECIFICATIONS - SAMPLE..............................................................................P-3
SPECIFICATIONS - ELECTRICAL.......................................................................P-4
SPECIFICATIONS - PHYSICAL...........................................................................P-5
CUSTOMER SERVICE, TECHNICAL ASSISTANCE AND FIELD SERVICE......P-6
RETURNING PARTS TO THE FACTORY...........................................................P-6
TRAINING ........................................................................................................P-6
DOCUMENTATION..............................................................................................P-6
COMPLIANCES ...................................................................................................P-7
SECTION 1. INTRODUCTION
1.1 OVERVIEW ..............................................................................................1-1
1.2 OXYGEN RANGE ON FRONT PANEL DIGITAL DISPLAY.....................1-2
1.3 OXYGEN RANGES FOR RECORDER READOUT..................................1-2
1.4 RECORDER VOLTAGE AND CURRENT OUTPUTS..............................1-3
1.5 AUTOMATIC PRESSURE COMPENSATION..........................................1-3
1.6 ALARM (OPTION)....................................................................................1-3
1.7 CASE MOUNTING OPTIONS ...................................................................1-3
1.8 ELECTRICAL POWER OPTIONS............................................................1-3
SECTION 2. UNPACKING AND INSTALLATION
2.1 UNPACKING ............................................................................................2-1
2.2 LOCATION ...............................................................................................2-1

CONTENTS
ii April 2000 Rosemount Analytical 245364-UModel 755A Oxygen Analyzer
SECTION 2. (CONTINUED)
2.2.1 Location and Mounting............................................................... 2-1
2.3 VOLTAGE REQUIREMENTS .................................................................. 2-1
2.4 ELECTRICAL CONNECTIONS................................................................ 2-2
2.4.1 Line Power Connections............................................................. 2-2
2.4.2 Recorder Connections................................................................ 2-2
2.4.3 Output Connections for Dual Alarm Option ................................ 2-5
2.5 CALIBRATION......................................................................................... 2-8
2.5.1 Zero Calibration Gas .................................................................. 2-8
2.5.2 Downscale Standard Gas........................................................... 2-8
2.5.3 Upscale Standard Gas ............................................................... 2-8
2.6 SAMPLE HANDLING............................................................................... 2-8
2.6.1 Sample Temperature Requirements........................................... 2-8
2.6.2 Sample Pressure Requirements: General................................. 2-9
2.6.3 Normal Operation at Positive Gauge Pressures......................... 2-10
2.6.4 Operation at Negative Gauge Pressures.................................... 2-10
2.6.5 Sample Flow Rate...................................................................... 2-10
2.6.6 Corrosive Gases........................................................................ 2-11
2.7 LEAK TEST.............................................................................................. 2-11
2.8 PURGE KIT (OPTIONAL) ........................................................................ 2-12
SECTION 3. INITIAL STARTUP AND CALIBRATION
3.1 SELECTION OF RECORDER OXYGEN RANGE ................................... 3-1
3.1.1 Recorder Oxygen Range Selection Procedure........................... 3-1
3.1.2 Readout of Applied Zero-Suppression Voltage on
Digital Display............................................................... 3-5
3.2 STARTUP PROCEDURE......................................................................... 3-6
3.3 CALIBRATION......................................................................................... 3-7
3.3.1 Calibration Using Digital Readout for Oxygen Readout.............. 3-7
3.3.2 Calibration Using Recorder for Oxygen Readout ....................... 3-7
3.3.3 Calibration with Downscale and Upscale Standard Gases......... 3-8
3.3.4 Calibration of Automatic Pressure Compensation...................... 3-9
3.4 COMPENSATION FOR COMPOSITION OF BACKGROUND GAS........ 3-10
3.4.1 Oxygen Equivalent Values of Gases.......................................... 3-11
3.4.2 Computing Adjusted Settings for Zero and Span Controls......... 3-11
3.5 DUAL ALARM OPTION ........................................................................... 3-13
3.5.1 Inital Calibration and Selection of Setpoints for Alarms.............. 3-13
3.5.2 Selection of Deadband............................................................... 3-14

CONTENTS
245364-U Rosemount Analytical April 2000 iii
Model 755A Oxygen Analyzer
SECTION 4. ROUTINE OPERATION
4.1 ROUTINE OPERATION ...........................................................................4-1
4.2 EFFECT OF BAROMETRIC PRESSURE CHANGES ON
INSTRUMENT READOUT............................................................4-1
4.3 CALIBRATION FREQUENCY ..................................................................4-1
SECTION 5. THEORY
5.1 PRINCIPLES OF OPERATION ................................................................5-1
5.2 VARIABLES INFLUENCING PARAMAGNETIC OXYGEN
MEASUREMENTS........................................................................5-5
5.2.1 Pressure Effects..........................................................................5-5
5.2.2 Temperature Effects....................................................................5-5
5.2.3 Interferents.................................................................................5-6
5.2.4 Vibration Effects..........................................................................5-6
5.3 ELECTRONIC CIRCUITRY......................................................................5-6
5.3.1 Detector/Magnet Assembly.........................................................5-7
5.3.2 Control Board and Associated Circuitry ......................................5-7
5.3.3 Case Board.................................................................................5-9
5.3.4 Isolated Current Output Board (Optional)....................................5-10
5.3.5 Alarm Option...............................................................................5-10
SECTION 6. ELECTRONIC CIRCUIT ANALYSIS
6.1 OVERVIEW ..............................................................................................6-1
6.2 ±15VDC POWER SUPPLY.......................................................................6-1
6.3 CASE HEATER CONTROL CIRCUIT ......................................................6-1
6.4 DETECTOR HEATER CONTROL CIRCUIT ............................................6-6
6.5 DETECTOR LIGHT SOURCE CONTROL CIRCUIT................................6-7
6.6 DETECTOR WITH FIRST STAGE AMPLIFIER AND PRESSURE
COMPENSATION CIRCUITS.......................................................6-8
6.7 BUFFER AMPLIFIERS U10 AND ASSOCIATED ANTICIPATION
FUNCTION....................................................................................6-12
6.8 DIGITAL OUTPUT CIRCUIT.....................................................................6-12
6.9 ANALOG OUTPUT CIRCUITS FOR RECORDER AND ALARMS...........6-13