Air-gap and liquid displacement techniques: Dielectric measurements without attached electrodes

Anyone engaged seriously in the business of performing measurements of dielectric constant and dissipation factor on the large variety of solid electrical insulating materials in use today sooner or later encounters materials which present real problems with respect to the proper choice of electrodes to use. Sommerman(1) has stated that "it is not an exaggeration to say that electrode problems are encountered in at least half of the dielectric investigations undertaken."