熱(re)電(dian)(dian)(dian)阻傳感(gan)器中(zhong)的(de)(de)(de)(de)熱(re)敏(min)電(dian)(dian)(dian)阻是***種(zhong)新型的(de)(de)(de)(de)半(ban)(ban)(ban)(ban)(ban)導(dao)(dao)(dao)(dao)體測溫(wen)(wen)元(yuan)件。半(ban)(ban)(ban)(ban)(ban)導(dao)(dao)(dao)(dao)體中(zhong)參加導(dao)(dao)(dao)(dao)電(dian)(dian)(dian)的(de)(de)(de)(de)是載(zai)(zai)流(liu)子(zi)(zi)，由(you)(you)于半(ban)(ban)(ban)(ban)(ban)導(dao)(dao)(dao)(dao)體中(zhong)載(zai)(zai)流(liu)子(zi)(zi)的(de)(de)(de)(de)數(shu)目遠(yuan)比(bi)金屬中(zhong)的(de)(de)(de)(de)自由(you)(you)電(dian)(dian)(dian)子(zi)(zi)數(shu)目少得(de)多，所(suo)以它的(de)(de)(de)(de)電(dian)(dian)(dian)阻率大。隨(sui)溫(wen)(wen)度(du)(du)的(de)(de)(de)(de)升高(gao)，半(ban)(ban)(ban)(ban)(ban)導(dao)(dao)(dao)(dao)體中(zhong)更多的(de)(de)(de)(de)價電(dian)(dian)(dian)子(zi)(zi)受(shou)熱(re)激(ji)發躍遷到較(jiao)高(gao)能***而產生新的(de)(de)(de)(de)電(dian)(dian)(dian)子(zi)(zi)—空(kong)穴對，因(yin)而參加到電(dian)(dian)(dian)的(de)(de)(de)(de)載(zai)(zai)流(liu)子(zi)(zi)數(shu)目增(zeng)加了，半(ban)(ban)(ban)(ban)(ban)導(dao)(dao)(dao)(dao)體的(de)(de)(de)(de)電(dian)(dian)(dian)阻率也就(jiu)降低了(電(dian)(dian)(dian)導(dao)(dao)(dao)(dao)率增(zeng)加)。因(yin)為載(zai)(zai)流(liu)子(zi)(zi)數(shu)目隨(sui)溫(wen)(wen)度(du)(du)上(shang)(shang)升按指數(shu)規(gui)律增(zeng)加，所(suo)以半(ban)(ban)(ban)(ban)(ban)導(dao)(dao)(dao)(dao)體的(de)(de)(de)(de)電(dian)(dian)(dian)阻率也就(jiu)隨(sui)溫(wen)(wen)度(du)(du)上(shang)(shang)升按指數(shu)規(gui)律下(xia)降。熱(re)敏(min)電(dian)(dian)(dian)阻正是利用半(ban)(ban)(ban)(ban)(ban)導(dao)(dao)(dao)(dao)體這種(zhong)載(zai)(zai)流(liu)子(zi)(zi)數(shu)隨(sui)溫(wen)(wen)度(du)(du)變(bian)化(hua)而變(bian)化(hua)的(de)(de)(de)(de)特性制成(cheng)的(de)(de)(de)(de)***種(zhong)溫(wen)(wen)度(du)(du)敏(min)感(gan)元(yuan)件。當溫(wen)(wen)度(du)(du)變(bian)化(hua)1℃時，某些半(ban)(ban)(ban)(ban)(ban)導(dao)(dao)(dao)(dao)體熱(re)敏(min)電(dian)(dian)(dian)阻的(de)(de)(de)(de)阻值變(bian)化(hua)將(jiang)達到(3～6)%。在***定條件下(xia)，根據測量熱(re)敏(min)電(dian)(dian)(dian)阻值的(de)(de)(de)(de)變(bian)化(hua)得(de)到溫(wen)(wen)度(du)(du)的(de)(de)(de)(de)變(bian)化(hua)壓力傳感(gan)器。
　　熱電阻傳感器安裝要求
　　對熱(re)電(dian)阻(zu)的(de)安裝，應注意有利于測溫準確，安全(quan)可考及維(wei)修(xiu)方(fang)便，而且不影(ying)響設備運行和(he)生產操作。要滿足以上要求(qiu)，在選(xuan)擇對熱(re)電(dian)阻(zu)的(de)安裝部位(wei)和(he)插入深度時要注意以下幾點:
　　1、為了使(shi)熱電阻的測量端與被測介(jie)質之(zhi)間有(you)充分的熱交換，應合理選擇測點(dian)位(wei)置，盡量避免在閥(fa)門，彎頭(tou)及管(guan)道和設備的死(si)角附近裝設熱電阻。
　　2、帶有(you)保護套管的熱電阻有(you)傳熱和(he)散(san)熱損失，為(wei)了減少(shao)測量誤(wu)差，熱電偶和(he)熱電阻應該(gai)有(you)足夠的插(cha)入深度：
　　(1)對于測量管(guan)道中心流(liu)體溫度的(de)熱電阻，***般(ban)都應將其測量端(duan)插入(ru)到管(guan)道中心處(垂直安裝(zhuang)或(huo)傾(qing)斜安裝(zhuang))。如被測流(liu)體的(de)管(guan)道直徑是200毫米(mi)(mi)，那熱電阻插入(ru)深度應選擇100毫米(mi)(mi);
　　(2)對于高溫高壓和高速流(liu)體(ti)的溫度測量(如主蒸汽(qi)溫度)，為了減小(xiao)保(bao)(bao)護(hu)(hu)套(tao)對流(liu)體(ti)的阻力和防止(zhi)保(bao)(bao)護(hu)(hu)套(tao)在(zai)流(liu)體(ti)作用(yong)下發生斷裂，可采取保(bao)(bao)護(hu)(hu)管淺(qian)插(cha)方(fang)式(shi)或采用(yong)熱套(tao)式(shi)熱電阻。淺(qian)插(cha)式(shi)的熱電阻保(bao)(bao)護(hu)(hu)套(tao)管，其插(cha)入主蒸汽(qi)管道的深度應不小(xiao)于75mm;熱套(tao)式(shi)熱電阻的標準插(cha)入深度為100mm;
　　(3)假如需要測(ce)量是煙(yan)(yan)道內煙(yan)(yan)氣(qi)的溫(wen)度(du)，盡(jin)管煙(yan)(yan)道直徑為4m，熱電阻插入深度(du)1m即可。
　　(4)當測量原件插入深(shen)度超過1m時(shi)，應盡可能(neng)垂直安裝(zhuang)，或加裝(zhuang)支撐架(jia)和保護(hu)套管稱(cheng)重傳感器。