Chapter I. THE THEORY OF THE ASPIRATION METHOD UNDER IDEAL CONDITIONS
§  1. Air ions (1)
§  2. Velocity field of air ions (4)
§  3. Arrangement of an aspiration counter and the principle of measurement of the air-ion spectrum (6)
§  4. Integral counter (8)
§  5. Solution of the equation of the integral counter (11)
§  6. Various integral counter types (14)
§  7. Differential counters of the first order (17)
§  8. Differential counter of the second order (22)
§  9. Counters with several collector plates (25)
§ 10. Counters with interplate air mixing (29)
§ 11. Measurement of the space charge density (32)
§ 12. Modulated counters (34)

Chapter II. DEVIATIONS FROM IDEAL CONDITIONS
§ 13. Factors causing disturbances and systematic measurement errors (39)
§ 14. The edge effect (41)
§ 15. Results of the experimental investigation of the edge effect (45)
§ 16. Effect of space charge on measurement results (50)
§ 17. Measurement methods based on the utilization of the electric field of the space charge (57)
§ 18. The electrode effect (60)
§ 19. Diffusion of air ions (64)
§ 20. Turbulent mixing of air in measuring capacitor (71)
§ 21. Results of the experimental investigation of the effect of turbulence (75)
§ 22. Long measuring capacitor with a turbulent air flow (84)
§ 23. The asymmetry of the measuring capacitor and the effect of gravitation of air ions (87)
§ 24. Adsorption of air ions (92)

Chapter III. PARAMETERS AND DESIGN PRINCIPLES OF ASPIRATION COUNTERS
§ 25. Classification of counter circuit arrangements (100)
§ 26. Current measurement by the charge accumulated in a capacitor (103)
§ 27. Current measurement based on the voltage drop across a resistance (106)
§ 28. Sensitivity of the integral counter (110)
§ 29. Calculation of air-ion spectral characteristics (113)
§ 30. Assessment of random errors in measuring the characteristics of the air-ion spectrum (118)
§ 31. Elimination of the effect of random voltage fluctuations on the measurement results (124)
§ 32. Prevention of the edge effect (128)
§ 33. Methods of determination of the effective capacitance of the measuring capacitor (132)
§ 34. Principles of the selection of the parameters and operating conditions of the integral counter (136)
§ 35. Brief survey of the designs of air-ion aspiration counters (143)
§ 36. Description of a universal integral air-ion counter (149)

SUPPLEMENTS
List of symbols (159)
Appendix I - Special factors in measurement at high altitudes (161)
Appendix II - Systems of units (165)
Bibliography (166)
List of Abbreviations (200)