Microwave Measurement System of Chinese Pill Material's Moisture Content Based on Microwave Resonator

摘要

A new microwave measurement method for moisture content of Chinese pill material is proposed in this paper. According to this method, a measurement system is designed for moisture content real-time measurement on Chinese pill production lines. In this system, moisture content can be measured by a specially designed microwave resonator which has a center hole. When Chinese pill material pass through the center hole, its density and moisture will cause resonant frequency excursion (RFE) and microwave attenuation (MA) of the resonator. Under the same moisture, density is only related to MA. If RFE and MA are detected, we can calculate moisture content of Chinese pill material, the change of density would not affect the calculating result of moisture content. In order to get high accuracy, a center-certain fuzzy clustering algorithm is proposed. According to the response characteristic of microwave resonator and the fuzzy clustering algorithm, we designed a high accuracy microwave measurement system which can measure moisture content on Chinese pill product lines. Experimental results showed that the measurement system had high accuracy on high speed production line; its accuracy varied from 92 percent to 96 percent in different months.