Small ion mobility characteristics under the Shiobara HVDC test line

A summary is presented of the experimental results of small ion mobility characteristics under the Shiobara HVDC (high-voltage direct-current) test line. An aspirator-type ion counter was developed to measure ion densities and ion mobilities simultaneously under a HVDC line where both electric field and ions exist together. Thereafter, ion mobility spectra and mean ion mobilities for positive and negative small ions were obtained with this ion counter under the test line as a result of a series of experiments extending through four seasons. Moreover, the accuracy of indirectly measured ion densities obtained from measured values of ion current density, electric field, and ion mobility was found to be within ±30% in comparison with directly measured ion densities with the ion counter through examination under the line