射she頻pin導dao納na物wu位wei開kai關guan的de探tan測ce極ji棒bang與yu金jin屬shu容rong器qi罐guan壁bi之zhi間jian具ju有you電dian容rong特te性xing,由you此ci構gou成cheng一yi個ge電dian橋qiao電dian路lu,振zhen蕩dang電dian路lu產chan生sheng的de射she頻pin振zhen蕩dang信xin號hao加jia在zai這zhe個ge電dian橋qiao上shang。當dang被bei測ce介jie質zhi未wei接jie觸chu到dao探tan測ce極ji棒bang時shi,電dian橋qiao處chu於yu平ping衡heng狀zhuang態tai,沒mei有you輸shu出chu信xin號hao。而er當dang被bei測ce介jie質zhi填tian充chong到dao探tan測ce極ji棒bang與yu罐guan壁bi之zhi間jian時shi,由you於yu被bei測ce介jie質zhi的de電dian特te性xing與yu空kong氣qi不bu同tong,會hui引yin起qi電dian橋qiao電dian路lu的de不bu平ping衡heng,從cong而er產chan生sheng輸shu出chu信xin號hao。