1. Purpose
2. Definitions
3. Formula Symbols
4. References
5. Electrical Parameters Near HVDC Transmission Lines
6. Electric-Field-Strength Measurements
6.1 Instrumentation and Principle of Operation
6.1.1 Field Mills (Generating Voltmeter)
6.1.2 Vibrating Plate Electric-Field Meters
6.2 Calibration of Instrumentation
6.2.1 Calibration Field Without Space Charge
6.2.1.1 Calibration in Ground Plane
6.2.1.2 Calibration Above Ground Plane
6.2.2 Calibration Field With Space Charge
6.2.2.1 Calibration in Ground Plane
6.2.2.2 Calibration Above Ground Plane
6.3 Measurements
6.3.1 Power Line Electric-Field-Strength Measurements
6.3.1.1 Ground-Plane Measurements
6.3.1.2 Above-Ground-Plane Measurements
6.3.2 Indoor Electric-Field-Strength Measurements
6.3.3 Above-Ground-Plane Electric field Measurements
         in the Absence of Space Charge
6.4 Sources of Measurement Error
7. Current-Density Measurements
7.1 Instrumentation and Principle of Operation
7.2 Calibration of Instrumentation
7.3 Measurements
7.3.1 Power-Line Current-Density Measurements
7.3.2 Indoor Current-Density Measurements
7.4 Sources of Measurement Error
8. Conductivity Measurements
8.1 Instrumentation and Principles of Operation
8.2 Calibration of Instrumentation
8.3 Measurements
8.4 Sources of Measurement Error
9. Monopolar Charge-Density Measurements
9.1 Instrumentation and Principle of Operation
9.2 Calibration of Instrumentation
9.3 Measurements
9.3.1 Power-Line Charge-Density Measurements
9.3.2 Indoor Charge-Density Measurements
9.4 Sources of Measurement Error
9.4.1 External Parameters Affecting Ion-Counter
         Operation
9.4.1.1 External Electric Field
9.4.1.2 Nonuniform Charge Density
9.4.1.3 Wind
9.4.2 Parameters Affecting Internal Operation of the
         Ion Counter
9.4.2.1 Fringing Electric Field
9.4.2.2 Coulomb Repulsion and Diffusion
9.4.2.3 Other Parameters
9.4.3 Charge-Density Measurement Above the Ground Plane
10. Net Space-Charge-Density Measurements
10.1 Instrumentation and Principle of Operation
10.1.1 Faraday Cage
10.1.2 Filter
10.2 Calibration of Faraday Cages and Filters
10.3 Measurements
10.3.1 Power-Line Space-Charge-Density Measurements
10.3.2 Indoor Space-Charge-Density Measurements
10.4 Sources of Measurement Error
10.4.1 Faraday Cages
10.4.2 Filters
TABLE
1. Normalized Electric-Field Strength Midway Between
FIGURES
1. Schematic View of a Bipolar High-Voltage DC Trans-
     mission Line
2. Simplified Schematic View of a Shutter-Type Electric
     Field Mill
3. Schematic View of a Cylindrical Field Mill
4. Schematic View of an Electric Field Near the Surface
     of a Ground-Referenced Cylindrical Field Mill in a
     Nearly Uniform Electric Field
5. Schematic View of Vibrating-Plate Electric-Field
     Meter Probe
6. Normalized Electric Field at the Surfaces of and
     Midway Between Semi-Infinite Parallel Plates
7. Schematic View of a Parallel-Plate System That
     Produces DC Fields With Ions
8. Lateral Electric-Field Profiles Measured at Ground
     Level for Fair Weather, Fog, and Rain Conditions
9. Schematic View of a Wilson Plate Mounted Flush with
     the Ground Plane
10. Schematic View of a Current Injection Circuit for
     Calibrating Electrometer Used with Wilson Plate
11. Lateral Ion Current-Density Profiles Measured at
     Ground Level for Fair Weather, Fog, and Rain Conditions
12. Schematic View of a Wilson Plate Resting on the Ground
     Plane
13. Errors for Current Sensors Located Above the Ground
     Plane
14. Schematic View of a Gerdien Tube
15. Features of the I-V Curve for a Gerdien Tube for the
     Operating Range From Conductivity Measurements to
     Ion Counting
16a. A Gerdien Tube Polarizing Potential Configuration
     Such That Ions Are Deflected at the Inlet
16b. Arrangements Where Fringing Fields Attract Ions to
     the Collector From Outside the Device
17. Parallel-Plate Ion Counter
18. Positive Charge-Density Measurements, pm, as a
     Function of Average Air Velocity in the Plane of
     Aperture
19. Ion Trajectories for Air Speed in the Plane of
     Aperture of 1 m/s
20. Ion-Counter Output Current as a Function of Polarizing
     Voltage for Different Plate Configurations
21. Schematic Views of the Ion Counter Above the Ground
     Plane in Vertical and Horizontal Orientations
22. Schematic View of a Parallelepiped Faraday Cage and
     Coordinate System for Eq 17
23. Diagram of the High-Impedance Voltage Follower Circuit
     Used to Measure the Potential at the Center of the
     Faraday Cage
24. Schematic View of a Filter for Measuring the Net Space
     Charge
25. Small Air Ion Density Plotted Versus Distance for
     Wind Speeds of 0 m/s, 4 m/s, and 8 m/s
26. Schematic View of a Hemispheric Cage Resting on the
     Ground Plane in a Uniform Vertical Electric Field, EO