物(wu)(wu)位(wei)(wei)測量(liang)通常指對工業生產過程中封閉式或(huo)敞開容器中物(wu)(wu)料（固(gu)體或(huo)液(ye)位(wei)(wei)）的高度(du)進行(xing)(xing)檢(jian)測；如果是(shi)對物(wu)(wu)料高度(du)進行(xing)(xing)連(lian)(lian)續的檢(jian)測，稱(cheng)為(wei)連(lian)(lian)續測量(liang)。如果只(zhi)對物(wu)(wu)料高度(du)是(shi)否到達某一位(wei)(wei)置進行(xing)(xing)檢(jian)測稱(cheng)為(wei)限(xian)位(wei)(wei)測量(liang)。完(wan)成這種測量(liang)任務(wu)的儀(yi)(yi)表(biao)叫做物(wu)(wu)位(wei)(wei)計。物(wu)(wu)位(wei)(wei)測量(liang)儀(yi)(yi)表(biao)用來監測液(ye)體或(huo)固(gu)體料位(wei)(wei)，包括漿料和顆(ke)粒狀固(gu)體。
按(an)測量手段來區分主要有(you)直讀式(shi)(shi)(shi)、浮(fu)力式(shi)(shi)(shi)（浮(fu)球、浮(fu)子、磁翻轉、電(dian)浮(fu)筒(tong)、磁致伸縮等(deng)）；回(hui)波(bo)反(fan)射式(shi)(shi)(shi)（超聲(sheng)、微波(bo)、導(dao)波(bo)雷達(da)等(deng)）；電(dian)容(rong)式(shi)(shi)(shi)；重錘探測式(shi)(shi)(shi)；音叉式(shi)(shi)(shi)；阻旋式(shi)(shi)(shi)；靜壓式(shi)(shi)(shi)等(deng)多種；其它還有(you)核輻(fu)射式(shi)(shi)(shi)、激光(guang)式(shi)(shi)(shi)等(deng)用于(yu)特殊場(chang)合的測量方(fang)法。
物(wu)(wu)位(wei)(wei)(wei)儀表(biao)的(de)命名方式(shi)通常(chang)由儀表(biao)的(de)測(ce)(ce)(ce)量(liang)(liang)手(shou)段、測(ce)(ce)(ce)量(liang)(liang)對(dui)象和測(ce)(ce)(ce)量(liang)(liang)目的(de)三個部分組成。例如音叉(cha)物(wu)(wu)位(wei)(wei)(wei)控(kong)制器(qi)、電浮筒液位(wei)(wei)(wei)計(ji)等。對(dui)于(yu)既能測(ce)(ce)(ce)量(liang)(liang)液位(wei)(wei)(wei)又可測(ce)(ce)(ce)量(liang)(liang)料位(wei)(wei)(wei)的(de)儀表(biao)則(ze)稱為(wei)物(wu)(wu)位(wei)(wei)(wei)計(ji)。例如超聲(sheng)物(wu)(wu)位(wei)(wei)(wei)計(ji)、微波物(wu)(wu)位(wei)(wei)(wei)計(ji)、導波雷(lei)達物(wu)(wu)位(wei)(wei)(wei)計(ji)等。
物位(wei)(wei)測量(liang)儀(yi)(yi)表(biao)是測量(liang)液(ye)(ye)(ye)態和(he)粉粒(li)狀(zhuang)材料的液(ye)(ye)(ye)面(mian)和(he)裝載高(gao)度的工業(ye)自動(dong)化儀(yi)(yi)表(biao)。測量(liang)塊狀(zhuang)、顆粒(li)狀(zhuang)和(he)粉料等固(gu)體物料堆積高(gao)度，或(huo)表(biao)面(mian)位(wei)(wei)置的儀(yi)(yi)表(biao)稱(cheng)為料位(wei)(wei)計(ji)；測量(liang)罐(guan)、塔和(he)槽等容(rong)(rong)器內液(ye)(ye)(ye)體高(gao)度，或(huo)液(ye)(ye)(ye)面(mian)位(wei)(wei)置的儀(yi)(yi)表(biao)稱(cheng)為液(ye)(ye)(ye)位(wei)(wei)計(ji)，又稱(cheng)液(ye)(ye)(ye)面(mian)計(ji)；測量(liang)容(rong)(rong)器中兩種互不溶解液(ye)(ye)(ye)體或(huo)固(gu)體與液(ye)(ye)(ye)體相(xiang)界面(mian)位(wei)(wei)置的儀(yi)(yi)表(biao)稱(cheng)為相(xiang)界面(mian)計(ji)。
