ABSTRACT
MEASUREMENT OF ELECTRIC FIELD AND ION-RELATED QUANTITIES*
Ronald H. McKnight
TABLE OF CONTENTS
I. Introduction 24
II. Definition of Terms 24
III. Measurement of Electric Field and Space Potential 26 A. Electric Field 26 B. Space Potential 30
IV. Measurement of Vertical Current Density 30
V. Measurement of Conductivity 32
VI. Measurement of Net Space Charge Density 36 A. Cage Methods 36 B. Filtration Methods 38
VII. Measurement of Unipolar Ion Density 39
VIII. Measurement of Ion Mobility and Species Identification 41
IX. Errors Associated with External Electric Fields and Off Ground Operation of Instruments 45 A. Effects Due to External Fields 45 B. Space Charge Effects 47
X. Applications of Measurements 48 A. HVDC Transmission Lines 48 B. Biological Exposure Systems 50 C. Room Measurements 51
Acknowledgments 51
References 52
24 Air Ions: Physical and Biological Aspects
I. INTRODUCTION
Measurements of various quantities to describe the electrical characteristics of the atmosphere have been made for many decades by atmospheric scientists using a variety of instruments and measurement techniques. The purpose of this chapter is to describe those techniques which have application in present-day ion-related research. References chosen are representative and it is not intended that they be exhaustive. Summaries, specialized texts," and proceedings of conferences' are excellent sources for more detailed discussions of particular topics and should be consulted by the interested reader.'
