Influence of Humidity on Variation of Ion Mobility with Life Time in Atmospheric Air

Using the time of flight method, the variations of ion mobility with both life time and atmospheric humidity were measured. At higher absolute humidity, mobility of the positive ion starts to decrease and saturate at a certain value in a shorter life time. Meanwhile, mobility of the negative ion is independent of life time and the value of it decreases as absolute humidity increases. Applying the experimental data to the coaxial cylinders in corona, the distributions of effective field and space charge density were calculated in different absolute humidity.