Enhanced accuracy in dielectric response material characterization by air reference method

Dielectric response measurements are an important technique to characterize dielectric materials. However, the electrode arrangements as well as the accuracy of the measurement setup limit the precision of this characterization, especially in case of solid dielectric materials. An air reference method and a contact-free electrode arrangement are described in this paper to enhance the dielectric characterization accuracy by avoiding problems introduced by electrode contacts. It is shown that by performing a calibration with electrode gap filled with air under the same conditions as the material is tested, the air reference method can improve the measurement accuracy substantially. This type of approach also eliminates the need of a detailed model of the analog measurement circuit. In conjunction with the contact-free measurements, the approach allows for avoiding complicated and time-consuming sample preparation procedures. The measurement methodology as well as the electrode arrangement and error increase estimates are presented and evaluated by using different dielectric response instruments and materials.