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鎧裝熱電偶具有能彎曲、耐高溫、熱響應時間快和堅固耐用等特點,它和工業用裝配式熱電偶一樣,作為測量溫度的傳感器,通常和顯示儀表、記錄儀表和電子調節器配套使用,同時,亦可以作為裝配式熱電偶的感溫元件,它可以直接測量各種生產過程中從0℃~1000℃范圍內的液體、蒸汽和氣體介質以及固體表面的溫度
工作原理(li)
鎧(kai)裝(zhuang)(zhuang)(zhuang)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶的(de)(de)工(gong)作原理是由(you)兩種不同成(cheng)份的(de)(de)導(dao)體兩端(duan)(duan)經(jing)焊接(jie),形成(cheng)回路(lu)(lu),直(zhi)接(jie)測溫(wen)(wen)端(duan)(duan)叫測量(liang)端(duan)(duan),接(jie)線(xian)端(duan)(duan)叫參比端(duan)(duan)。當測量(liang)端(duan)(duan)和(he)參比端(duan)(duan)存在溫(wen)(wen)差時,就(jiu)會在回路(lu)(lu)中產(chan)(chan)生熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)流,接(jie)上顯示儀(yi)表,儀(yi)表上就(jiu)會指示出熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶所產(chan)(chan)生的(de)(de)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)勢(shi)的(de)(de)對應溫(wen)(wen)度值。鎧(kai)裝(zhuang)(zhuang)(zhuang)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶的(de)(de)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)勢(shi)將隨著測量(liang)端(duan)(duan)的(de)(de)溫(wen)(wen)度升高而增(zeng)長(chang),熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)勢(shi)的(de)(de)大小只和(he)鎧(kai)裝(zhuang)(zhuang)(zhuang)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶導(dao)體材質以及兩端(duan)(duan)溫(wen)(wen)差有關(guan),和(he)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)極的(de)(de)長(chang)度,直(zhi)徑無關(guan)。鎧(kai)裝(zhuang)(zhuang)(zhuang)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶的(de)(de)結構(gou)是由(you)導(dao)體,絕(jue)緣氧(yang)化(hua)鎂(mei)和(he)1Cr18Ni9Ti不銹鋼(gang)保(bao)護管經(jing)多(duo)次拉制而成(cheng),鎧(kai)裝(zhuang)(zhuang)(zhuang)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶產(chan)(chan)品主要由(you)接(jie)線(xian)盒,接(jie)線(xian)端(duan)(duan)子(zi)和(he)鎧(kai)裝(zhuang)(zhuang)(zhuang)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶組(zu)(zu)成(cheng)基(ji)本結構(gou),并配以各種安裝(zhuang)(zhuang)(zhuang)固定裝(zhuang)(zhuang)(zhuang)置組(zu)(zu)成(cheng)。
主要技術(shu)指(zhi)標
測溫范圍(wei)和(he)準確(que)度(du)
類別 | 代號 | 分度號 | 套管外徑 mm | 常用溫度 ℃ | ***高使用 溫度 ℃ | 允許偏差 △t | |
測量范圍 ℃ | 允差值 | ||||||
鎳鉻-鎳硅 | WRNK | K | ≥Φ3 | 800 | 1000 | 0~1000 | ±2.5℃或±0.0075|t| |
鎳鉻-銅鎳 | WREK | E | ≥Φ3 | 600 | 700 | 0~700 | ±2.5℃或±0.0075|t| |
銅-銅鎳 | WRCK | T | ≥Φ3 | 350 | 400 | <-200 | 未作規定 |
-40~350 | ±1℃或±0.0075|t| |
注:1)t為被測溫度的******值。
鎧裝熱(re)電偶(ou)熱(re)響(xiang)應時(shi)間
在溫度出現階躍變化時,熱電偶的輸出變化至相當于該階躍變化的50%,所需要的時間稱為熱響應時間,用T0.5表示。
鎧裝熱(re)電偶熱(re)響應時(shi)間不大于下表的規定:
熱響應時間T0.5S | 接殼式(shi) | 絕緣式(shi) |
套管(guan)直(zhi)徑(min) | ||
2.0 | 0.4 | 0.5 |
3.0 | 0.6 | 1.2 |
4.0 | 0.8 | 2.5 |
5.0 | 1.2 | 4.0 |
6.0 | 2.0 | 6.0 |
8.0 | 4.0 | 8.0 |
絕緣電阻(zu)
當周(zhou)圍空氣(qi)溫(wen)度(du)為20±15℃,相(xiang)對濕度(du)不大于80﹪時,絕(jue)緣型(xing)鎧裝熱電(dian)偶的(de)偶絲與(yu)外套(tao)管之(zhi)間的(de)絕(jue)緣電(dian)阻值應符合(he)下表規定。
套(tao)管直徑(jing)mm | 試驗電(dian)壓V-D.C | 絕(jue)緣(yuan)電(dian)阻MΩ.m |
0.5~1.5 | 50±5 | ≥1000 |
>1.5 | 500±50 | ≥1000 |
型號表示
W | R | 規格 | 內容 | ||||||
N | 鎳鉻(ge)-鎳硅 | ||||||||
E | 鎳鉻(ge)-銅鎳 | ||||||||
C | 銅-銅鎳 | ||||||||
測 溫 元 件 材 料(liao) | K | ||||||||
鎧 裝 式 | - | 1 | 無固定裝置式(shi) | ||||||
2 | 固定卡套螺紋 | ||||||||
3 | 可動卡(ka)套螺(luo)紋 | ||||||||
4 | 固定(ding)卡套法蘭 | ||||||||
5 | 可(ke)動卡套(tao)法蘭 | ||||||||
安 裝 固 定 形 式 | 0 | 無(wu)接線(xian)盒式 | |||||||
2 | 防濺式 | ||||||||
3 | 防(fang)水式(shi) | ||||||||
8 | 手柄式 | ||||||||
8 | 小接(jie)線盒(he)式 | ||||||||
9 | 帶補償導線(xian) | ||||||||
接 線 盒 形 式(shi) | 1 | 絕緣式 | |||||||
2 | 接(jie)殼(ke)式 | ||||||||
7 | 絕(jue)緣(yuan)式(手柄式) | ||||||||
8 | 接(jie)殼式(手柄式) | ||||||||
工 作 端(duan) 形 式 | 3 | 3對 | |||||||
4 | 4對(dui) | ||||||||
5 | 5對 | ||||||||
6 | 6對 | ||||||||
多 對 式 | |||||||||
W | R | □ | K | - | □ | □ | □ | □ |