New Moisture Sensor with Microstripline for High Moist Leaves in Green Tea Production (Neuer Feuchtesensor mit Mikrostreifenleitung für hochfeuchte Blätter in der Produktion von grünem Tee)

Abstract

This paper describes a new sensor for the production of green tea. It can measure the moisture content as high as 160 to 300% on dry basis by use of microwave at 3 GHz. The wave traveling down along a microstripline detects the information on the moisture contents of the green tea leaves overlaid on the microstripline. The moisture content of the leaves is calculated from two signals of the ratio of attenuation and phase shift of the waves traveling over the microstripline. The error of the measurement was about 3% of the readings.

Dynamic measurement of moisture content using microwaves for moisture evaluation of agricultural products

“…An important quality factor of an agricultural product is its moisture content. In electromagnetic wave technology, transmission line methods using waveguides or coaxial lines and resonant cavities have been reported for grain moisture measurements . A measurement method in the microwave frequency range is highly desirable for nondestructive and noncontact measurements on a continuous grain stream.…”