1.熱電偶熱電特性不穩定所引起的誤差
redianouwendujijingguoyiduanshijianshiyong，shouqishiyongdehuanjingyingxiang，qibenshenderedianxingnengjianghuichanshengyidingdebianhua，zegairedianouwendujijiliangdedaodewenduyuzhenshiwenduyouyidingdepianli。影響熱電偶穩定性的主要因素有：
（1）被測物對熱電偶電極的汙染和腐蝕；
（2）熱電極受外力作用而產生的變形所引起的形變應力；
（3）感溫電極在高溫下微觀結構晶粒發生變化；
（4）熱電極受暴露在空氣中發生氧化等。
2.熱電偶不均勻性的影響
熱(re)電(dian)偶(ou)的(de)均(jun)勻(yun)性(xing)是(shi)指(zhi)熱(re)電(dian)偶(ou)熱(re)電(dian)極(ji)材(cai)料(liao)的(de)均(jun)勻(yun)程(cheng)度(du)。如(ru)果(guo)熱(re)電(dian)偶(ou)中(zhong)的(de)兩(liang)個(ge)熱(re)電(dian)極(ji)材(cai)料(liao)是(shi)均(jun)勻(yun)的(de)，則(ze)熱(re)電(dian)偶(ou)回(hui)路(lu)產(chan)生(sheng)的(de)熱(re)電(dian)勢(shi)和(he)兩(liang)端(duan)溫(wen)度(du)差(cha)呈(cheng)正(zheng)相(xiang)關(guan)，而(er)與(yu)沿(yan)熱(re)電(dian)極(ji)長(chang)度(du)的(de)溫(wen)度(du)梯(ti)度(du)無(wu)關(guan)。
3.測量溫度點的選擇
xuanzeheshidecewendianshianzhuangredianoushishifenzhongyaodekaolvyinsu，xuanzejuyoudaibiaoxingdecewendian，duiyuzhenggeshengchanhuanjingjuyouteshudeyiyi。weizhixuanzebudang，zekongzhihejiliangjianghaowuyiyi。zaiceliangdian，redianoucharudeshenduyeduiwenduceliangchanshengyingxiang，dangwaibuhuanjinghebeicewuwenducunzaiwenduchashi，redianoushangceliangdewenduhuisuizhechuanganqideyanchangeryuwaijiehuanjingchanshengrejiaohuan，jierdailaijiliangwucha。youyuhuanjingwenduqianbianwanhua，zhezhongwenduwuchashibukeguliangde。chuleyouyucharushenqianfashengrechuandaoyinrudewuchayiwai，redianouwaibubaohuguancaizhiyehuiyinruceliangwucha。lirujinshucaizhidebaohuguan，qidaorexingnengjiaohao，yincizaiceliangguochengzhongxuyaojiangqicharugengshenyibimianreliangsunshi。duiyutaocicaizhidebaohuguan，zexuyaojiangqicharuqianyixie。
4.響應時間的影響
隻(zhi)有(you)被(bei)測(ce)對(dui)象(xiang)和(he)測(ce)溫(wen)元(yuan)件(jian)溫(wen)度(du)一(yi)致(zhi)時(shi)，測(ce)溫(wen)元(yuan)件(jian)的(de)溫(wen)度(du)才(cai)能(neng)穩(wen)定(ding)，此(ci)時(shi)二(er)者(zhe)達(da)到(dao)熱(re)平(ping)衡(heng)，這(zhe)是(shi)接(jie)觸(chu)法(fa)測(ce)溫(wen)的(de)基(ji)本(ben)原(yuan)理(li)。被(bei)測(ce)對(dui)象(xiang)和(he)測(ce)溫(wen)元(yuan)件(jian)溫(wen)度(du)達(da)到(dao)一(yi)致(zhi)需(xu)要(yao)一(yi)定(ding)時(shi)間(jian)來(lai)實(shi)現(xian)，該(gai)時(shi)間(jian)的(de)長(chang)短(duan)，主(zhu)要(yao)由(you)測(ce)溫(wen)元(yuan)件(jian)的(de)熱(re)響(xiang)應(ying)性(xing)能(neng)決(jue)定(ding)，即(ji)熱(re)響(xiang)應(ying)時(shi)間(jian)。熱(re)響(xiang)應(ying)時(shi)間(jian)受(shou)傳(chuan)感(gan)器(qi)的(de)結(jie)構(gou)和(he)計(ji)量(liang)條(tiao)件(jian)影(ying)響(xiang)，通(tong)過(guo)實(shi)驗(yan)，不(bu)同(tong)條(tiao)件(jian)下(xia)的(de)響(xiang)應(ying)時(shi)間(jian)差(cha)別(bie)很(hen)大(da)。靜(jing)止(zhi)的(de)氣(qi)態(tai)介(jie)質(zhi)，兩(liang)者(zhe)需(xu)要(yao)持(chi)續(xu)接(jie)觸(chu)30分鍾以上才能達到溫度平衡，如靜態的液體，溫度平衡時間將縮短到5分鍾。
在(zai)實(shi)際(ji)工(gong)程(cheng)應(ying)用(yong)中(zhong)，被(bei)測(ce)對(dui)象(xiang)的(de)溫(wen)度(du)經(jing)常(chang)是(shi)處(chu)於(yu)不(bu)斷(duan)變(bian)化(hua)的(de)狀(zhuang)態(tai)，瞬(shun)間(jian)變(bian)化(hua)的(de)時(shi)間(jian)很(hen)短(duan)，因(yin)此(ci)對(dui)傳(chuan)感(gan)器(qi)的(de)要(yao)求(qiu)也(ye)相(xiang)對(dui)較(jiao)高(gao)，一(yi)般(ban)要(yao)求(qiu)其(qi)響(xiang)應(ying)能(neng)力(li)為(wei)ms級ji別bie。如ru響xiang應ying能neng力li不bu足zu，則ze出chu現xian測ce量liang滯zhi後hou現xian象xiang。因yin此ci選xuan擇ze傳chuan感gan器qi要yao選xuan擇ze響xiang應ying速su度du快kuai的de。計ji量liang端duan直zhi徑jing是shi影ying響xiang響xiang應ying速su度du的de重zhong要yao因yin素su。如ru果guo偶ou絲si較jiao細xi，則ze響xiang應ying時shi間jian較jiao短duan。
5.熱輻射的影響
dangyongredianouceliangluzhongwendushi，luneigaowenwutiduiredianouderefushe，huiyinqiredianouwendushenggao。ruguoluneideqitijiadingweitoumingde，redianouhelubizhijiandewenchabijiaodashi，namenengliangjiaohuanzhihouyehuidailaicewenfangmiandewucha。zengjiarechuandaonenggouyouxiaodejiangdizhebufenwucha，ranglubidewenduheredianouwendujiejin。
6.熱阻抗增加的影響
dangredianouchuyugaowendegongkuanghuanjingxia，qitaibeicejiezhihuijiangbaohuguanbiaocenghuichenshaorong，yinqibaohuguanrezukangzengjia。ruguojiezhishirongti，namezaicaozuozhonghuichuxianluzhadechendianchendiandeluzhahuizengjiaredianouxiangyingshijian，zhishiwendufangmianhuibiandi。yincidingqijianzhahuobudingshidechoujianredianoudegongzuozhuangtai，nenggoujishidefaxianredianouchanshengdeyichang，jianshaoceliangwucha。
7.熱電偶絲不均質引起誤差
根(gen)據(ju)上(shang)述(shu)測(ce)量(liang)原(yuan)理(li)，當(dang)熱(re)電(dian)偶(ou)的(de)偶(ou)絲(si)均(jun)質(zhi)時(shi)，根(gen)據(ju)均(jun)質(zhi)回(hui)路(lu)定(ding)則(ze)，長(chang)度(du)對(dui)計(ji)量(liang)的(de)結(jie)果(guo)沒(mei)有(you)影(ying)響(xiang)。而(er)實(shi)際(ji)情(qing)況(kuang)是(shi)，廠(chang)家(jia)在(zai)進(jin)行(xing)偶(ou)絲(si)生(sheng)產(chan)時(shi)，通(tong)常(chang)會(hui)因(yin)為(wei)溫(wen)度(du)等(deng)原(yuan)因(yin)，導(dao)致(zhi)偶(ou)絲(si)粗(cu)細(xi)不(bu)均(jun)，呈(cheng)竹(zhu)節(jie)狀(zhuang)，甚(shen)至(zhi)出(chu)現(xian)嚴(yan)重(zhong)的(de)打(da)卷(juan)現(xian)象(xiang)。另(ling)外(wai)在(zai)後(hou)期(qi)的(de)加(jia)工(gong)中(zhong)會(hui)出(chu)現(xian)其(qi)他(ta)問(wen)題(ti)，對(dui)熱(re)電(dian)偶(ou)進(jin)行(xing)的(de)反(fan)複(fu)加(jia)工(gong)，會(hui)讓(rang)熱(re)電(dian)偶(ou)出(chu)現(xian)畸(ji)變(bian)從(cong)而(er)失(shi)去(qu)均(jun)質(zhi)。在(zai)進(jin)行(xing)測(ce)溫(wen)工(gong)作(zuo)時(shi)，很(hen)多(duo)偶(ou)絲(si)位(wei)於(yu)高(gao)溫(wen)區(qu)，如(ru)果(guo)不(bu)具(ju)備(bei)均(jun)值(zhi)性(xing)，且(qie)環(huan)境(jing)溫(wen)度(du)變(bian)化(hua)，那(na)麼(me)熱(re)電(dian)偶(ou)局(ju)部(bu)就(jiu)會(hui)出(chu)現(xian)寄(ji)生(sheng)熱(re)電(dian)動(dong)勢(shi)，從(cong)而(er)引(yin)入(ru)誤(wu)差(cha)。
從熱電偶的基本工作原理、jutideshiyongfangfaheshengchanzhizuoguochengzhongcunzaidewentidengfangmianjinxingshenrufenxi，dedaoleredianouwendujiliangchanshengwuchadezhuyaoyuanyin，zairedianoudezhizuoheshiyongzhong，chuanganqicharuweizhiyushenqian、熱電偶對溫度的響應時間、環境對熱電偶的熱輻射、熱阻抗改變、redianousibujunzhidengdoushichanshengjiliangwuchadezhuyaoyinsu，yincitishengwendujiliangdezhunqueduyaocongshangshuyinsuzhongjianxiaohebimian。fenxiredianouwendujiliangdewuchayuanyin，duishijigongchengyingyongjuyouyidingdezhidaoyiyi。
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