PREH壓(ya)(ya)力(li)變(bian)送器其測原理是：流(liu)程壓(ya)(ya)力(li)和參考壓(ya)(ya)力(li)分(fen)別作用于(yu)集成(cheng)硅(gui)壓(ya)(ya)力(li)敏感元件的(de)兩端(duan)，其差壓(ya)(ya)使硅(gui)片變(bian)形(位移很(hen)小，僅μm級(ji))，以使硅(gui)片上用半導體技術制(zhi)成(cheng)的(de)全動(dong)態惠斯登(deng)電(dian)(dian)橋(qiao)在外部電(dian)(dian)流(liu)源驅動(dong)下輸(shu)出(chu)正比(bi)于(yu)壓(ya)(ya)力(li)的(de)mV級(ji)電(dian)(dian)壓(ya)(ya)信(xin)(xin)(xin)號。由于(yu)硅(gui)材料(liao)的(de)彈性極(ji)佳(jia)，所以輸(shu)出(chu)信(xin)(xin)(xin)號的(de)線(xian)(xian)性度及(ji)變(bian)差指標(biao)均很(hen)高(gao)。工作時，PREH壓(ya)(ya)力(li)變(bian)送器將被測物理量轉換成(cheng)mV級(ji)的(de)電(dian)(dian)壓(ya)(ya)信(xin)(xin)(xin)號，并(bing)送往放(fang)大倍數(shu)很(hen)高(gao)而又(you)可以互相(xiang)抵消溫度漂(piao)移的(de)差動(dong)式放(fang)大器。放(fang)大后的(de)信(xin)(xin)(xin)號經(jing)電(dian)(dian)壓(ya)(ya)電(dian)(dian)流(liu)轉換變(bian)換成(cheng)相(xiang)應(ying)(ying)的(de)電(dian)(dian)流(liu)信(xin)(xin)(xin)號，再(zai)經(jing)過非線(xian)(xian)性校正，最后產生(sheng)與輸(shu)入(ru)壓(ya)(ya)力(li)成(cheng)線(xian)(xian)性對(dui)應(ying)(ying)關系的(de)標(biao)準電(dian)(dian)流(liu)電(dian)(dian)壓(ya)(ya)信(xin)(xin)(xin)號。