在化(hua)工應(ying)用(yong)(yong)領(ling)域，壓力變送(song)(song)器(qi)(qi)起著非常重要的作用(yong)(yong)，其應(ying)用(yong)(yong)也非常廣泛。壓力變送(song)(song)器(qi)(qi)種(zhong)類較多(duo)，按(an)照測量對象來劃分(fen)，可以分(fen)為******壓力變送(song)(song)器(qi)(qi)、表(biao)壓變送(song)(song)器(qi)(qi)和(he)差壓變送(song)(song)器(qi)(qi)三種(zhong)。根(gen)據環境條件的不(bu)同，應(ying)用(yong)(yong)工況、安裝(zhuang)條件等要素的不(bu)同，變送(song)(song)器(qi)(qi)的選(xuan)型也有不(bu)同的要求。   

壓力(li)測量領(ling)域(yu)變送(song)器的類型選擇

壓(ya)力(li)(li)(li)(li)變(bian)送(song)(song)(song)器(qi)在壓(ya)力(li)(li)(li)(li)測(ce)量領域中應用較多的(de)是中低表壓(ya)壓(ya)力(li)(li)(li)(li)變(bian)送(song)(song)(song)器(qi)、中高表壓(ya)壓(ya)力(li)(li)(li)(li)變(bian)送(song)(song)(song)器(qi)、******壓(ya)力(li)(li)(li)(li)變(bian)送(song)(song)(song)器(qi)和(he)中低表壓(ya)單法(fa)蘭隔(ge)膜(mo)密封式(shi)變(bian)送(song)(song)(song)器(qi)。按(an)照測(ce)量安(an)裝方(fang)式(shi)的(de)不(bu)(bu)同(tong)，變(bian)送(song)(song)(song)器(qi)可再分為(wei)管(guan)道直連(lian)式(shi)安(an)裝和(he)導壓(ya)管(guan)取壓(ya)安(an)裝兩種類型。在微(wei)小(xiao)(xiao)壓(ya)力(li)(li)(li)(li)狀態下，由(you)于直接(jie)測(ce)量壓(ya)力(li)(li)(li)(li)可能會導致不(bu)(bu)穩定波動的(de)出現(xian)，所以，當測(ce)量不(bu)(bu)高于500Pa 的(de)微(wei)小(xiao)(xiao)壓(ya)力(li)(li)(li)(li)時(shi)，選擇差壓(ya)變(bian)送(song)(song)(song)器(qi)更為(wei)合理。  

差(cha)(cha)(cha)壓(ya)(ya)(ya)(ya)(ya)和液(ye)(ye)位(wei)(wei)(wei)測(ce)(ce)(ce)量(liang)(liang)領(ling)域的(de)(de)變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)類型選擇(ze)所謂差(cha)(cha)(cha)壓(ya)(ya)(ya)(ya)(ya)測(ce)(ce)(ce)量(liang)(liang)，是(shi)指使(shi)(shi)用變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)測(ce)(ce)(ce)量(liang)(liang)的(de)(de)壓(ya)(ya)(ya)(ya)(ya)力(li)(li)進行差(cha)(cha)(cha)減得(de)出壓(ya)(ya)(ya)(ya)(ya)力(li)(li)差(cha)(cha)(cha)值。在液(ye)(ye)位(wei)(wei)(wei)測(ce)(ce)(ce)量(liang)(liang)領(ling)域，就可以(yi)通(tong)(tong)過差(cha)(cha)(cha)壓(ya)(ya)(ya)(ya)(ya)測(ce)(ce)(ce)量(liang)(liang)方法來(lai)獲得(de)測(ce)(ce)(ce)量(liang)(liang)結果(guo)。液(ye)(ye)位(wei)(wei)(wei)測(ce)(ce)(ce)量(liang)(liang)領(ling)域可使(shi)(shi)用的(de)(de)變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)有(you)差(cha)(cha)(cha)壓(ya)(ya)(ya)(ya)(ya)變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)、高(gao)差(cha)(cha)(cha)壓(ya)(ya)(ya)(ya)(ya)變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)、法蘭安裝(zhuang)式差(cha)(cha)(cha)壓(ya)(ya)(ya)(ya)(ya)變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)和隔(ge)膜密封(feng)式雙法蘭差(cha)(cha)(cha)壓(ya)(ya)(ya)(ya)(ya)變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)。常壓(ya)(ya)(ya)(ya)(ya)容器(qi)(qi)(qi)(qi)(qi)液(ye)(ye)位(wei)(wei)(wei)測(ce)(ce)(ce)量(liang)(liang)時(shi)(shi)，因容器(qi)(qi)(qi)(qi)(qi)與大氣相連，宜采(cai)用壓(ya)(ya)(ya)(ya)(ya)力(li)(li)變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)或(huo)(huo)者單法蘭隔(ge)膜密封(feng)式壓(ya)(ya)(ya)(ya)(ya)力(li)(li)變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)進行測(ce)(ce)(ce)量(liang)(liang)；針(zhen)對密封(feng)的(de)(de)容器(qi)(qi)(qi)(qi)(qi)測(ce)(ce)(ce)量(liang)(liang)其(qi)液(ye)(ye)位(wei)(wei)(wei)壓(ya)(ya)(ya)(ya)(ya)力(li)(li)時(shi)(shi)，因容器(qi)(qi)(qi)(qi)(qi)的(de)(de)密負壓(ya)(ya)(ya)(ya)(ya)室有(you)可能存在氣相的(de)(de)揮發(fa)，或(huo)(huo)者是(shi)容器(qi)(qi)(qi)(qi)(qi)的(de)(de)下端采(cai)用了氮(dan)封(feng)。所以(yi)在測(ce)(ce)(ce)量(liang)(liang)其(qi)液(ye)(ye)壓(ya)(ya)(ya)(ya)(ya)時(shi)(shi)，如果(guo)選用法蘭安裝(zhuang)式變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)，則負壓(ya)(ya)(ya)(ya)(ya)室需要引導壓(ya)(ya)(ya)(ya)(ya)管連通(tong)(tong)，而選用隔(ge)膜密封(feng)式變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)的(de)(de)話，那(nei)么正負壓(ya)(ya)(ya)(ya)(ya)室都須(xu)***使(shi)(shi)用遠傳法蘭連通(tong)(tong)。針(zhen)對敞(chang)開的(de)(de)水(shui)池(chi)，如果(guo)池(chi)底有(you)淤泥，那(nei)么可以(yi)選擇(ze)使(shi)(shi)用單法蘭密封(feng)隔(ge)膜式壓(ya)(ya)(ya)(ya)(ya)力(li)(li)變(bian)(bian)(bian)(bian)送(song)(song)(song)器(qi)(qi)(qi)(qi)(qi)來(lai)測(ce)(ce)(ce)量(liang)(liang)其(qi)液(ye)(ye)位(wei)(wei)(wei)。  

流(liu)量(liang)(liang)(liang)測(ce)量(liang)(liang)(liang)領(ling)域的變(bian)送(song)器(qi)類型(xing)選擇(ze)   流(liu)量(liang)(liang)(liang)測(ce)量(liang)(liang)(liang)一般選擇(ze)差(cha)壓(ya)(ya)變(bian)送(song)器(qi)和隔膜(mo)密封式雙法蘭差(cha)壓(ya)(ya)變(bian)送(song)器(qi)，差(cha)壓(ya)(ya)變(bian)送(song)器(qi)需要搭配孔(kong)板、阿牛巴(ba)和文丘里等節流(liu)裝置，而測(ce)出(chu)來的結果也是(shi)(shi)對差(cha)壓(ya)(ya)值(zhi)。如果是(shi)(shi)對蒸汽或者氣體(ti)等介質(zhi)進行測(ce)量(liang)(liang)(liang)，還(huan)需要通過(guo)二(er)次表或者 DCS/PLC 等上位系統進行相應的運算得出(chu)流(liu)量(liang)(liang)(liang)值(zhi)。  

當(dang)然(ran)，壓(ya)力(li)變送器在(zai)化工領(ling)域應用(yong)非常廣泛(fan)，在(zai)壓(ya)力(li)變送器選型(xing)中需要具(ju)體結(jie)合(he)應用(yong)環(huan)境的化學(xue)特性(xing)，充分考慮到溫(wen)度、濃度、腐蝕性(xing)等(deng)綜(zong)合(he)因素，再通過衡(heng)量其經濟性(xing)，選擇***合(he)理(li)的壓(ya)力(li)變送器變送器類型(xing)，使其更好滿足化工生產活動。