Capacitive Sensor with Deeper Sensing Extent for Measuring Moisture in Pressboard
Wanquan Li · Yibiao jishu yu chuanganqi · 2003
Presents a capacitive sensor with deeper sensing extent for detecting moisture content in pressboard.In form of electrical fringing field between a pair of adjustable electrodes,it can feel water content changing in the deep of pressboard.Under a low frequency sinual driving voltage,the output voltage from equivalent circuit of the sensor with pressboard provides both magnitude and phase related to moisture content in pressboard,which can be used to obtain the moisture content in pressboard with help of certain functions.The reasonable structure designed for the pressboard in larger thickness can meet the demands including high sensitive,deeper detecting extent,stable properties and be easy to fix.A moisture measuring system,including the sensor,can be applied in measuring moisture in pressboard of transformer coils during the drying process.