1st Edition

Thermocouples Theory and Properties

By Daniel D. Pollock Copyright 1991

    Thermocouples: Theory and Properties provides the basis for the examination and explanation of thermoelectric phenomena and their correlations with other physical properties. These results are applied and account for the properties and deviations of commercial materials in the temperature ranges of most common industrial usage.

    This book is written expressly for non-scientists and is an effective tool for the busy technician or engineer working with thermoelectric thermometry in metallurgical, chemical, petroleum, pharmaceutical, and food processing areas. It is also beneficial for use in quality control and research and development applications. The book provides more than the usual superficial presentations of thermoelectric properties; it explains the "why" as well as the "how" and "what" of thermoelectric behaviors. These answers are important because only a suitable combination of theory and practice can lead to the understanding required for optimum thermometric applications under the multitude of applications encountered in industry and science.

    INTRODUCTION. THERMOELECTRICITY. RELATED THERMAL EFFECTS. DRUDE-LORENTZ THEORY OF METALS. BEGINNINGS OF SOLID STATE THEORY. Black-Body Radiation. Electron Emission. Bases for Modern Theory. SUGGESTED READING. STATISTICAL TREATMENT OF ELECTRONS. NEWTONIAN CONCEPTS. SCHRÖDINGER'S EQUATION. LIMITATIONS ON SCHRÖDINGER'S EQUATION. ELECTRONS IN POTENTIAL WELLS. One-Dimensional Wells. Three-Dimensional Wells. THE PRINCIPLE OF EXCLUSION. QUANTUM NUMBERS. ELECTRON CONFIGURATIONS OF ATOMS. SUGGESTED READING . SOLID-STATE THEORIES. SOMMERFELD THEORY. THE FERMI-DIRAC THEORY. The Fermi Energy. The Fermi-Dirac Function. COMPARISON OF CLASSICAL AND MODERN STATISTICS. THE FERMI-SOMMERFELD THEORY. Metals. Heat Capacity. Electrical Conductivity-Normal Metals. BAND THEORY. Relation to Fermi-Sommerfeld Theory. BRILLOUIN ZONE THEORY. Applications of the Brillouin Theory. ELECTRICAL CONDUCTIVITY OF SEMICONDUCTORS. Intrinsic Conduction. Electron Properties. Extrinsic Conduction. SUGGESTED READING. THERMOELECTRIC PHENOMENA. RELATIVE SEEBECK COEFFICIENT. PELTIER EFFECT. THOMSON EFFECT. THERMODYNAMIC INTERRELATIONS. Fundamental Theorem. The Role of Entropy. Relation of the Peltier Effect to the Thomson Effect. Relation of the RSC to the Thomson Effect. ABSOLUTE EMF AND THE THOMSON EFFECT. Thermoelectric Laws. UTILITY OF ASC. THERMOELECTRIC CIRCUIT ANALYSES. REFERENCES. SUGGESTED READING. MODERN THEORIES OF THERMOELECTRICITY. ROLE OF HEAT CAPACITY. Normal Metallic Elements. Transition Elements. Semiconductors. ROLE OF ELECTRICAL CONDUCTIVITY. Normal Metallic Elements. Transition Metals. Semimetals. ROLE OF INTERNAL POTENTIALS. Normal Metallic Elements. Transition Elements. Alternate Evaluation of the Conduction Function. Semiconductors. RELATIONS TO OTHER PHYSICAL PROPERTIES. RELATIVE THERMOELECTRIC PROPERTIES. SUGGESTED READING. VARIATIONS OF THE FERMI ENERGY. TEMPERATURE. EFFECTS OF ALLOYING ELEMENTS IN NORMAL METALS. EFFECTS OF ALLOYING ELEMENTS IN TRANSITION METALS. Dilute Alloys. Concentrated Alloys. STRESS EFFECTS. THERMOELECTRIC INSTABILITY. REFERENCES. SOME EFFECTS OF ALLOYING. ALLOYS OF MONOVALENT METALS. ALLOYS OF MULTIVALENT METALS. ALLOYS OF TRANSITION METALS. Normal-Metals Alloying Elements. Transition-Metal Alloying Elements. REFERENCES. SUGGESTED READING. STANDARD THERMOELEMENTS (DILUTE ALLOYS). PLATINUM AND ITS ALLOYS (TYPES S, R, AND B). The Influence of Alloying with Rhodium. Factors Affecting the Use of Platinum-Base Thermocouples. NICKEL AND ITS ALLOYS (TYPES K, E, AND N). The Short-Range Order Hypothesis. The Effects of Magnetic Transformations. Alumel (Type KN). Nicrosil (Type NP). Chromel (Type KP). Nisil (Type NN). Limitations on the Use of Nickel-Base Thermocouples. IRON ALLOYS (TYPE JP). SOME NONSTANDARD THERMOCOUPLES. 19 Alloy-20 Alloy Thermocouple. Tungsten-Rhenium Thermocouples. Other Platinum Alloy Thermocouples. IRIDIUM-RHODIUM/IRIDIUM THERMOCOUPLES. PLATINEL THERMOCOUPLES. THERMOCOUPLE LEADS (EXTENSION WIRES). REFERENCES. SUGGESTED READING-MAGNETIC EFFECTS. CONSTANTANS. BINARY ALLOY THEORY. TERNARY ALLOY THEORY. EFFECT OF TEMPERATURE. THERMOELECTRIC PROPERTIES OF BINARY ALLOYS. THERMOELECTRIC PROPERTIES OF TERNARY ALLOYS. Scattering of Hybridized s-d Electrons. Temperature Dependence of d-Level Holes. DESIGN OF CONSTANTAN-TYPE ALLOYS (TYPES EN, JN, OR TN). REFERENCES. THERMOELECTRIC APPLICATIONS OF SEMICONDUCTORS. THEORY. PRACTICE. PELTIER MATERIALS. SUGGESTED READING. THERMOELECTRICITY AS A RESEARCH TOOL. PHASE BOUNDARIES. IMPERFECTION DENSITY. BAND STRUCTURE. PURITY EVALUATION. REFERENCES. APPENDICES. THE CONTACT POTENTIAL. THE DEBYE THEORY OF HEAT CAPACITY. METHODS FOR APPROXIMATING MAGNETIC PARAMTERS OF NICKEL-BASE THERMOELECTRIC ALLOYS. Numbers of Effective Nearest Neighbors in an Electronic Spin Cluster. Paramagnetic Transformation Temperatures. Magnetic Transformation Temperatures. INDEX

    Biography

    DanielD. Pollock