A Century of Grain and Seed Moisture Measurement by Sensing Electrical Properties

摘要

The importance of moisture measurement in grain and seed is discussed, and a brief history of the development of electrical moisture sensing instruments, based on sensing the electrical properties of these materials, is presented. Data are presented graphically on the permittivities or dielectric properties of grain and seed, showing their variation with frequency, moisture content, temperature, and bulk density, and references are cited for further information. More recent developments in higher frequency and microwave measurements for moisture content and bulk density sensing are briefly described, and numerous studies are cited providing sources of information on these newer techniques.