電容式液位計的測量原理與優勢

　　采用(yong)測(ce)(ce)(ce)量(liang)(liang)電(dian)(dian)(dian)(dian)(dian)容(rong)的(de)(de)(de)(de)(de)變化來(lai)測(ce)(ce)(ce)量(liang)(liang)液(ye)(ye)(ye)(ye)(ye)面(mian)的(de)(de)(de)(de)(de)高低的(de)(de)(de)(de)(de)。它是一根金屬棒(bang)(bang)插(cha)入盛(sheng)液(ye)(ye)(ye)(ye)(ye)容(rong)器內(nei)，金屬棒(bang)(bang)作為(wei)(wei)電(dian)(dian)(dian)(dian)(dian)容(rong)的(de)(de)(de)(de)(de)一個極，容(rong)器壁作為(wei)(wei)電(dian)(dian)(dian)(dian)(dian)容(rong)的(de)(de)(de)(de)(de)另一極。兩電(dian)(dian)(dian)(dian)(dian)極間的(de)(de)(de)(de)(de)介(jie)質(zhi)即為(wei)(wei)液(ye)(ye)(ye)(ye)(ye)體及其上面(mian)的(de)(de)(de)(de)(de)氣體。由(you)于(yu)液(ye)(ye)(ye)(ye)(ye)體的(de)(de)(de)(de)(de)介(jie)電(dian)(dian)(dian)(dian)(dian)常(chang)數(shu)(shu)ε1和液(ye)(ye)(ye)(ye)(ye)面(mian)上的(de)(de)(de)(de)(de)介(jie)電(dian)(dian)(dian)(dian)(dian)常(chang)數(shu)(shu)ε2不同(tong)，比如：ε1》ε2，則當液(ye)(ye)(ye)(ye)(ye)位升高時，兩電(dian)(dian)(dian)(dian)(dian)極間總的(de)(de)(de)(de)(de)介(jie)電(dian)(dian)(dian)(dian)(dian)常(chang)數(shu)(shu)值(zhi)隨(sui)之(zhi)加大因而電(dian)(dian)(dian)(dian)(dian)容(rong)量(liang)(liang)增(zeng)大。反(fan)之(zhi)當液(ye)(ye)(ye)(ye)(ye)位下降，ε值(zhi)減小，電(dian)(dian)(dian)(dian)(dian)容(rong)量(liang)(liang)也(ye)減小。所以，可通過(guo)兩電(dian)(dian)(dian)(dian)(dian)極間的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)容(rong)量(liang)(liang)的(de)(de)(de)(de)(de)變化來(lai)測(ce)(ce)(ce)量(liang)(liang)液(ye)(ye)(ye)(ye)(ye)位的(de)(de)(de)(de)(de)高低。電(dian)(dian)(dian)(dian)(dian)容(rong)液(ye)(ye)(ye)(ye)(ye)位計的(de)(de)(de)(de)(de)靈(ling)敏(min)度(du)主要取決于(yu)兩種介(jie)電(dian)(dian)(dian)(dian)(dian)常(chang)數(shu)(shu)的(de)(de)(de)(de)(de)差值(zhi)，而且(qie)，只有ε1和ε2的(de)(de)(de)(de)(de)恒定才能保證液(ye)(ye)(ye)(ye)(ye)位測(ce)(ce)(ce)量(liang)(liang)準(zhun)確，因被測(ce)(ce)(ce)介(jie)質(zhi)具有導(dao)電(dian)(dian)(dian)(dian)(dian)性，所以金屬棒(bang)(bang)電(dian)(dian)(dian)(dian)(dian)極都有絕緣層覆蓋。

　　傳感器無機械可動部(bu)分，結(jie)構簡單、可靠;精確度(du)高;檢測端(duan)消耗電能(neng)小，動態響應快;維護(hu)方便(bian)，壽命長。被測介質(zhi)需為導(dao)電率不低(di)于10-3S/M的非結(jie)晶導(dao)電液(ye)體。

　　被(bei)測(ce)液(ye)(ye)體的(de)介電常數不穩定會引起誤差(cha)。電容式液(ye)(ye)位計(ji)一般用于調節(jie)池(chi)、清(qing)水池(chi)測(ce)量。(注：液(ye)(ye)化氣是(shi)否會對測(ce)量造成影響未知(zhi)待確定)