To sum up, our terms of reference will include the operating principles, basic features and techniques (including auxiliary apparatus) of the two important electrical methods of measurement: the bridge method and the potentiometer method, assuming that the measuring circuit is balanced by hand.Translated from the Russian by Boris Kuznetsov CONTENTS Introduction 7Chapter One. BASIC DEFINITIONS AND CONCEPTS 11 1-1. Classification of Methods of Measurement 11 1-2. General Remarks on Sensitivity 15Chapter Two. PRIMARY AND SECONDARY STANDARDS OF ELECTRI­ CAL UNITS 202-1. General 202-2. Standards of Resistance 222-3. Standards of Capacitance 252-4. Standards of Inductance 272-5. Standards of E.M.F. 29Chapter Three. DIRECT-CURRENT AND ALTERNATING-CURRENT NULL DETECTORS 31 3-1. Types of Null Detectors 31 3-2. The Moving-coil Galvanometer 34 3-3. Valve-type A. C. Null Detectors 39Chapter Four. AUXILIARY EQUIPMENT 53 4-1. Types of Auxiliary Equipment. Requirements 534-2. D. C. Power Supplies  544-3. Voltage Stabilizers 564-4. A. C. Supplies 624-5. Auxiliary Amplifiers 67Chapter Five. THE D.C. BRIDGE METHOD 70 5-1. The Bridge Circuit. Definition of the Bridge Method 705-2. The Four-arm (Wheatstone) Bridge 715-3. The Kelvin Double Bridge 785-4. The Sensitivity of D.C. Bridges 865-5. Unbalanced Bridges. Comparison Sets 945-6. Construction of D. C. Bridges 110Chapter Six. ALTERNATING-CURRENT BRIDGE MEASUREMENTS 114 6-1. Properties and Classification of A. C. Bridges 114 6-2. The Sensitivity of A. C. Bridges 1236-3. Balancing and Circle Diagrams of A.C. Bridges 134 6-4. Balance Convergence of A. C. Bridges 142 6-5. Independence of Adjustments and Measurement 151 6-6. Basic Types of A. C. Bridges 156 6-7. Quasi-balanced A. C. Bridges 1806-8. A. C. Percentage Bridges 187Chapter Seven. THE D. C. POTENTIOMETER METHOD1937-1. Basic Principles and Development of the Potentiometer Method 1937-2. Practical D. C. Potentiometers 2107-3. The Sensitivity of D. C. Potentiometers 2217-4. Applications of D. C. Potentiometers 227Chapter Eight. THE ALTERNATING-CURRENT POTENTIOMETER METHOD 2328-1. Special Features of the A.C. Potentiometer Method  2328-2. Principles of Construction and Practical A.C. Potentiometers 236 8-3. Applications of A. C. Potentiometers 244Chapter Nine. CONTROL OF STRAY EFFECTS 247 9-1. Principal Sources of Stray Effects 247 9-2. Control of Stray Effects in D. C. MeasuringCircuits 2509-3. Control of Stray Effects in A.C. Measuring Circuits 252Index 263