Electrochemistry of Zirconia Gas Sensors Book

Preface     xi
Acknowledgments     xiii
About the Author     xv
Introduction to Electrochemistry of Solid Electrolyte Gas Sensors     1
Electrochemistry of Zirconia Solid Electrolytes as the Basis for Understanding Electrochemical Gas Sensors     1
Solid Oxygen-Ionic Electrolytes     1
Transport Properties     4
Electrophysical Properties of Solid Electrolytes     6
Aging of Solid Electrolytes     11
Single-Phase Solid Electrolytes     12
Two-Phase Solid Electrolytes     14
An Electron Model of Solid Oxygen-Ionic Electrolytes Used in Gas Sensors     15
Electrode Processes in Solid Electrolyte Sensors     30
Electrode Reaction within the Triple-Phase Boundary     30
Diffusion of Oxygen Atoms     33
Role of the Electric Double Layer in Electrode Reactions     36
Helmholtz Double Layer     36
Gouy-Chapman Double Layer     37
Stern Modification of the Diffuse Double Layer     38
References     39
Mathematical Modeling of Zirconia Gas Sensors with Distributed Parameters     43
Complete Mathematical Model of Electrochemical Gas Sensors     43
Modeling Interactions of Oxygen with theZirconia Sensor     50
Modeling Interactions of Various Gases with Non-Nernstian Zirconia Sensors     60
Description of Non-Nernstian Behavior     60
Non-Nernstian Zirconia-Based N[subscript x] Sensors     62
Mathematical Formulation of Zirconia-Based NO[subscript x] Sensors     64
Numerical Mathematical Models of Zirconia Gas Sensors     71
Identification Parameters of Mathematical Models     80
Verification Adequacy of Mathematical Models to Real Gas Sensors     83
Nomenclature     87
Subscripts     88
References     89
Metrological Characteristics of Non-Nernstian Zirconia Gas Sensors     93
Non-Nernstian Zirconia Gas Sensors     93
Mixed-Potential NO[subscript x] Sensors     93
Description of Nernstian Behavior     97
Mixed-Potential Gas Sensors     98
Concepts of the Total-NO[subscript x] Sensor Based on Mixed Potential     101
Development of the NO[subscript x] Sensor's Design     104
Mixed-Potential Hydrocarbon Sensors     115
Impedance-Based Zirconia Gas Sensors     119
Future Trends     125
References     128
Zirconia Sensors for Measurement of Gas Concentration in Molten Metals      135
Zirconia Sensors for the Measurement of Oxygen Activity in Melts     135
Polycrystalline Zirconia Sensors     135
Pe' Parameter Measurements and Sensing Properties     138
Single-Crystal Zirconia Sensors     143
Zirconia Sensors Based on Shaped Eutectic Composites     154
Impedance Method for the Analysis of In-Situ Diagnostics and the Control of an Electrolyte/Liquid-Metal Electrode Interface     161
Galvano-Harmonic Method     163
Impulse Galvanic-Static Method     170
Measuring Oxygen Concentration in Lead-Bismuth Heat Carriers     175
Regulation of Oxygen Partial Pressure in Melts by Zirconia Pumps     176
Characteristics of Lamellar Oxygen Pumps     176
Potentiometric Mode of the Oxygen Pump     177
Galvano-Static Mode of the Oxygen Pump     186
Characteristics of Cylindrical Oxygen Pumps     188
Potentiometric Mode     188
Galvano-Static Mode     191
References     192
Manufacturing Technologies of Zirconia Gas Sensors     197
Vacuum-Tight Technologies of Joining Zirconia to Ceramic Insulators     197
Vacuum-Tight Technologies of Joining Zirconia to Sensor Construction Materials     207
Nanotechnologies for Zirconia Gas Sensors     213
Limitations of Existing Technologies and Future Trends     218
References     222
Errors of Measurement of Zirconia Gas Sensors     227
Bases of Errors Theory in Relation to Electrochemical Gas Sensors     227
Analysis of Systematic Errors of Zirconia Gas Sensors     232
Analysis of the Main Components of Errors of Zirconia Gas Sensors     234
Error Stipulated by the Reference Pressure Instability     239
Error Stipulated by the Variations of Emf     240
Error Stipulated by Inaccuracy of Setting and Measurement of the SEC Temperature     241
Calculation of Errors on the Basis of Experimental Data     243
References     251
Organization and Planning of Testing Zirconia Sensors     253
Main Principles of Testing Zirconia Sensors     253
Sensing Mechanisms of Zirconia Gas Sensors     253
Sensor Structures and Devices     254
Zirconia Sensor Systems     254
Measurement and Control Systems     254
Selecting the Number of Independent Variables (Factors)     256
Determination of Experimental Data Volume     258
Sequence of Experiment     260
Data Processing      260
Planning of Experiments     265
Development of the Industrial Prototype of the Sensor     266
Product Verification     266
Training     267
Reliability Testing of Zirconia Gas Sensors     267
References     271
Index     273