傳感器是能夠受規定的被測量並按照一定的規律轉換成可用輸出信號的器件或裝置的總稱,通常由敏感元件和轉換元件組成
，WRN-231熱電偶，WZP-130熱電阻。當傳感器的輸出為規定的標準信號時，則稱為變送器
，如茂尚品牌的MS-WB溫度變送器
，MS-YB壓力變送器
，MS-YBL液位變送器。  

   biansongqidegainianshijiangfeibiaozhundianxinhaozhuanhuanweibiaozhundianxinhaodeyiqi，chuanganqizeshijiangwulixinhaozhuanhuanweidianxinhaodeqijian
，guoquchangjiangwulixinhao
，xianzaiqitaxinhaoyeyoule。yiciyibiaozhixianchangceliangyibiaohuojidikongzhibiao
，erciyibiaozhiliyongyicibiaoxinhaowanchengqitagongneng：諸如控製，顯示等功能的儀表。

   傳感器和變送器本是熱工儀表的概念。傳感器是把非電物理量如溫度、壓力
、液位、物料
、氣體特性等轉換成電信號或把物理量如壓力、液(ye)位(wei)等(deng)直(zhi)接(jie)送(song)到(dao)變(bian)送(song)器(qi)。變(bian)送(song)器(qi)則(ze)是(shi)把(ba)傳(chuan)感(gan)器(qi)采(cai)集(ji)到(dao)的(de)微(wei)弱(ruo)的(de)電(dian)信(xin)號(hao)放(fang)大(da)以(yi)便(bian)轉(zhuan)送(song)或(huo)啟(qi)動(dong)控(kong)製(zhi)元(yuan)件(jian)。或(huo)將(jiang)傳(chuan)感(gan)器(qi)輸(shu)入(ru)的(de)非(fei)電(dian)量(liang)轉(zhuan)換(huan)成(cheng)電(dian)信(xin)號(hao)同(tong)時(shi)放(fang)大(da)以(yi)便(bian)供(gong)遠(yuan)方(fang)測(ce)量(liang)和(he)控(kong)製(zhi)的(de)信(xin)號(hao)源(yuan)。根(gen)據(ju)需(xu)要(yao)還(hai)可(ke)將(jiang)模(mo)擬(ni)量(liang)變(bian)換(huan)為(wei)數(shu)字(zi)量(liang)。傳(chuan)感(gan)器(qi)和(he)變(bian)送(song)器(qi)一(yi)同(tong)構(gou)成(cheng)自(zi)動(dong)控(kong)製(zhi)的(de)監(jian)測(ce)信(xin)號(hao)源(yuan)。不(bu)同(tong)的(de)物(wu)理(li)量(liang)需(xu)要(yao)不(bu)同(tong)的(de)傳(chuan)感(gan)器(qi)和(he)相(xiang)應(ying)的(de)變(bian)送(song)器(qi)。還(hai)有(you)一(yi)種(zhong)變(bian)送(song)器(qi)不(bu)是(shi)將(jiang)物(wu)理(li)量(liang)變(bian)換(huan)成(cheng)電(dian)信(xin)號(hao)，如(ru)一(yi)種(zhong)鍋(guo)爐(lu)水(shui)位(wei)計(ji)的(de)“差壓變送器”，他(ta)是(shi)將(jiang)液(ye)位(wei)傳(chuan)感(gan)器(qi)裏(li)的(de)下(xia)部(bu)的(de)水(shui)和(he)上(shang)部(bu)蒸(zheng)汽(qi)的(de)冷(leng)凝(ning)水(shui)通(tong)過(guo)儀(yi)表(biao)管(guan)送(song)到(dao)變(bian)送(song)器(qi)的(de)波(bo)紋(wen)管(guan)兩(liang)側(ce)，以(yi)波(bo)紋(wen)管(guan)兩(liang)側(ce)的(de)差(cha)壓(ya)帶(dai)動(dong)機(ji)械(xie)放(fang)大(da)裝(zhuang)置(zhi)用(yong)指(zhi)針(zhen)指(zhi)示(shi)水(shui)位(wei)的(de)一(yi)種(zhong)遠(yuan)方(fang)儀(yi)表(biao)。當(dang)然(ran)還(hai)有(you)把(ba)電(dian)氣(qi)模(mo)擬(ni)量(liang)變(bian)換(huan)成(cheng)數(shu)字(zi)量(liang)的(de)也(ye)可(ke)以(yi)叫(jiao)變(bian)送(song)器(qi)。以(yi)上(shang)隻(zhi)是(shi)從(cong)概(gai)念(nian)上(shang)說(shuo)明(ming)傳(chuan)感(gan)器(qi)和(he)變(bian)送(song)器(qi)的(de)區(qu)別(bie)。