关键词: 颗粒饲料, 介电特性, 含水率, 温度, 无损检测

Abstract: In order to explore the dielectric properties of pellet feed and achieve the rapid detection of moisture content in pellet feeds, livestock and poultry and aquatic pellet feed is taken as the research object. This paper studied the effects of frequency (1～200 kHz), temperature (10～30℃) and moisture content (8.8%～19.1%) on the relative dielectric constant and established the corresponding prediction model of moisture content using coaxial-line cylinder capacitor. The results showed that the dielectric constant of pellet feed increased with the increase of moisture content and temperature, decreased with the increase of the frequency. With the coefficient of determination and the standard deviation as evaluation index, the moisture content of pig and poultry pellet was the best at 10 kHz. And the coefficient of determination was 0.996 6 and 0.998 4, respectively. At 200 kHz, the moisture content model of the aquatic product feed was the best, the determination coefficient was 0.999 2. It was verified by experiment that the absolute error range of moisture content of pellet feed was predicted to be ±1.1%, indicating that it was feasible to predict the moisture content of pellet feed based on the dielectric properties, which was instructive to develop moisture dector for pellet feed.

Key words: pellet feed, dielectric properties, moisture content, temperature, nondestructive testing