在此前的文章中，小編曾經寫過化工行業中雷達液位計的相關知識，包括測量原理，選型問題，安裝問題。最近正好有用戶咨詢超聲波雷達液位計的問題，借此機會(hui)，我們今(jin)天(tian)一起來看看在化工行業中超(chao)聲(sheng)波液位計的選型要(yao)點。

超聲波液位計向物料表面發射超聲波脈沖信號，物料反射回波，回波信號被傳感器接收。智能轉換器測量傳感器發射和接收脈沖信號的時間差，并根據時間差和聲速計算出傳感器到物料表面的距離。然后根據傳感器的安裝高度計算實際物位高度，超聲波液位計一般內置溫度傳感器，以補償傳播介質溫度變化引起的聲速變化。超聲波的特點有，可用于開口容器、水池等的液位測量。重量輕、壽命長、價格低、安裝方便、穩定性好。適用于腐蝕性、高粘度、易燃、有毒液體、漿液、污水等連續非接觸式液位測量，不受介質密度、介電常數、電導率等影響。

超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計(ji)的(de)(de)(de)選型要(yao)點有，當被測(ce)(ce)介(jie)質(zhi)(zhi)為揮(hui)發性液(ye)(ye)體或含有大量(liang)水(shui)蒸氣、灰塵、氣泡、懸浮(fu)顆粒等時，不(bu)(bu)宜(yi)(yi)(yi)使(shi)用(yong)(yong)(yong)超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計(ji)。因為聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)遇到這些物(wu)質(zhi)(zhi)，會發生不(bu)(bu)規(gui)則反射和散射，這些物(wu)質(zhi)(zhi)也(ye)會吸收聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)，造(zao)成(cheng)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)衰減，影響(xiang)測(ce)(ce)量(liang)效果。超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計(ji)不(bu)(bu)能(neng)用(yong)(yong)(yong)于真(zhen)空場合，也(ye)不(bu)(bu)宜(yi)(yi)(yi)用(yong)(yong)(yong)于負壓(ya)場合。由于超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)的(de)(de)(de)傳(chuan)(chuan)播(bo)需要(yao)空氣介(jie)質(zhi)(zhi)，稀薄的(de)(de)(de)空氣環境不(bu)(bu)利于超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)的(de)(de)(de)傳(chuan)(chuan)播(bo)，聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)的(de)(de)(de)衰減增加，導致測(ce)(ce)量(liang)誤差增大，甚至無(wu)法測(ce)(ce)量(liang)。超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計(ji)必須在(zai)(zai)能(neng)充分反射和傳(chuan)(chuan)輸聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)的(de)(de)(de)介(jie)質(zhi)(zhi)中使(shi)用(yong)(yong)(yong)，超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計(ji)不(bu)(bu)宜(yi)(yi)(yi)用(yong)(yong)(yong)于吸收聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)能(neng)力(li)強(qiang)的(de)(de)(de)介(jie)質(zhi)(zhi)。超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計(ji)一(yi)般只能(neng)在(zai)(zai)常溫常壓(ya)范圍內使(shi)用(yong)(yong)(yong)，溫度(du)一(yi)般不(bu)(bu)能(neng)超(chao)過(guo)100℃。壓(ya)力(li)過(guo)大，會增強(qiang)對(dui)超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)聲(sheng)(sheng)(sheng)(sheng)(sheng)速的(de)(de)(de)抑制作用(yong)(yong)(yong)，影響(xiang)測(ce)(ce)量(liang)精度(du)，甚至無(wu)法測(ce)(ce)量(liang)。探測(ce)(ce)器與轉換器的(de)(de)(de)連接電纜(lan)應采取抗電磁干擾措施，EOEG裝置(zhi)中，超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計(ji)主要(yao)用(yong)(yong)(yong)于雨(yu)水(shui)收集(ji)池、污水(shui)池等地下水(shui)池的(de)(de)(de)液(ye)(ye)位(wei)(wei)(wei)測(ce)(ce)量(liang)。設備內部有影響(xiang)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)傳(chuan)(chuan)播(bo)的(de)(de)(de)障礙物(wu)，不(bu)(bu)宜(yi)(yi)(yi)使(shi)用(yong)(yong)(yong)超(chao)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計(ji)。

化工(gong)行業的設備(bei)中(zhong)液位測量(liang)的工(gong)況復雜多變，應根據測量(liang)場(chang)合(he)的具體工(gong)作條件和測量(liang)要求，結合(he)各(ge)種液位儀表的特點和適(shi)用(yong)性(xing)，選擇(ze)安全(quan)、可靠、準確、易于安裝和維護、經濟適(shi)用(yong)的液位計(ji)。