一、熱電偶介紹
熱(re)(re)(re)電(dian)(dian)偶是利用熱(re)(re)(re)電(dian)(dian)效應(ying)作為(wei)測量原理(li)的一種(zhong)無源傳感器(qi)。所謂(wei)的熱(re)(re)(re)電(dian)(dian)效應(ying)即兩(liang)種(zhong)不(bu)同(tong)成(cheng)份(fen)的導體(稱為(wei)熱(re)(re)(re)電(dian)(dian)偶絲材或熱(re)(re)(re)電(dian)(dian)極)兩(liang)端接(jie)合(he)成(cheng)回(hui)路(lu),當(dang)兩(liang)個接(jie)合(he)點(dian)的溫度不(bu)同(tong)時,在回(hui)路(lu)中就會產生電(dian)(dian)動勢的現象(xiang)。所以根據組成(cheng)熱(re)(re)(re)電(dian)(dian)偶兩(liang)種(zhong)絲材的材質不(bu)同(tong)可以得到(dao)不(bu)同(tong)類型的熱(re)(re)(re)電(dian)(dian)偶,不(bu)同(tong)型號之前也存在一定的差異。
二、k型熱電偶與e型熱電偶區別
K型熱(re)電(dian)偶與E型熱(re)電(dian)偶的(de)區別在于(yu)熱(re)電(dian)動(dong)勢、靈(ling)敏度、穩定性(xing)和(he)均勻性(xing)、抗氧化性(xing)能(neng)和(he)價格。
K型(xing)熱電偶(ou)適(shi)用于氧(yang)化(hua)性(xing)(xing)惰性(xing)(xing)氣(qi)(qi)氛(fen),而E型(xing)熱電偶(ou)適(shi)用于氧(yang)化(hua)性(xing)(xing)和(he)惰性(xing)(xing)氣(qi)(qi)氛(fen),但(dan)不能在高溫下使用硫、還原(yuan)性(xing)(xing)或還原(yuan)性(xing)(xing)氣(qi)(qi)氛(fen)中和(he)真空中。E型(xing)熱電偶(ou)具有穩定性(xing)(xing)好、抗氧(yang)化(hua)性(xing)(xing)能好、價格便宜等(deng)優(you)點,但(dan)熱電動(dong)勢較(jiao)大,靈敏度最(zui)高,適(shi)用于高濕度氣(qi)(qi)氛(fen),但(dan)對于高濕度腐蝕不甚靈敏。
三、k型熱電偶和t型熱電偶的區別
k型熱電(dian)偶(ou)和(he)t型熱電(dian)偶(ou)的區別主要在于(yu)測量范圍(wei):
k型(xing),可(ke)以(yi)測(ce)量-200度(du)(du)到1000多(duo)度(du)(du)的范圍(wei)(wei),缺(que)點(dian)(dian)是(shi)超過(guo)居里(li)點(dian)(dian)的時候會有特征曲線的跳(tiao)變,大約150度(du)(du)左右(you)。t型(xing)是(shi)非磁(ci)性材料,沒(mei)有居里(li)點(dian)(dian),所以(yi)特征曲線更連貫,效果好一些。溫度(du)(du)范圍(wei)(wei)-200度(du)(du)到350度(du)(du)。