Measurement of permittivity and dissipation factor without attached electrodes

When the determination of permittivity is made using attached electrodes, it is necessary to know the dimensions of the specimen. The thickness measurement is especially difficult, particularly for relatively thin specimens. For example, when the specimen is 10 mils thick an error of 0.1 mil in the thickness determination will result in a 1 percent error in the calculated permittivity. The difficulties become increasingly greater as the thickness of the specimens decreases.