Microwave Resonator as a Dielectric Object Sorting Device: Advantages and Limitations

Microwave resonators have been used as sensors for sorting dielectric objects. Differences in volume or mass can be distinguished amnong objects of irregular shape but of uniform dielectric properties. Moisture content, or other permittivity-dependent qualities can be distinguished independent of mass or volume when objects are of uniform shape. Fundamental principles of the shape-independent and size-independent measurements are discussed, and experimental results are given. Measurements are fast, nondestructive and potentially continuous.