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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(zuo)原理
鎧(kai)(kai)(kai)裝熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶(ou)(ou)(ou)的(de)(de)(de)工作(zuo)原理是由兩(liang)種不同成份的(de)(de)(de)導(dao)體兩(liang)端(duan)(duan)(duan)(duan)經(jing)焊接(jie),形成回路,直接(jie)測(ce)溫(wen)(wen)(wen)端(duan)(duan)(duan)(duan)叫測(ce)量端(duan)(duan)(duan)(duan),接(jie)線端(duan)(duan)(duan)(duan)叫參(can)比端(duan)(duan)(duan)(duan)。當測(ce)量端(duan)(duan)(duan)(duan)和參(can)比端(duan)(duan)(duan)(duan)存在(zai)溫(wen)(wen)(wen)差(cha)時,就會(hui)在(zai)回路中產(chan)生(sheng)熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)流,接(jie)上(shang)顯示儀(yi)表(biao),儀(yi)表(biao)上(shang)就會(hui)指示出熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶(ou)(ou)(ou)所產(chan)生(sheng)的(de)(de)(de)熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)勢(shi)的(de)(de)(de)對(dui)應(ying)溫(wen)(wen)(wen)度值(zhi)。鎧(kai)(kai)(kai)裝熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶(ou)(ou)(ou)的(de)(de)(de)熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)勢(shi)將隨著測(ce)量端(duan)(duan)(duan)(duan)的(de)(de)(de)溫(wen)(wen)(wen)度升(sheng)高而增長,熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)勢(shi)的(de)(de)(de)大小只和鎧(kai)(kai)(kai)裝熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶(ou)(ou)(ou)導(dao)體材質以及兩(liang)端(duan)(duan)(duan)(duan)溫(wen)(wen)(wen)差(cha)有關,和熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)的(de)(de)(de)長度,直徑無關。鎧(kai)(kai)(kai)裝熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶(ou)(ou)(ou)的(de)(de)(de)結(jie)(jie)構是由導(dao)體,絕緣(yuan)氧化鎂和1Cr18Ni9Ti不銹(xiu)鋼保護管(guan)經(jing)多次拉制而成,鎧(kai)(kai)(kai)裝熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶(ou)(ou)(ou)產(chan)品主要(yao)由接(jie)線盒,接(jie)線端(duan)(duan)(duan)(duan)子(zi)和鎧(kai)(kai)(kai)裝熱(re)(re)(re)(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)偶(ou)(ou)(ou)組成基本結(jie)(jie)構,并(bing)配(pei)以各種安(an)裝固定裝置(zhi)組成。
主要技術指標(biao)
測溫范圍和準確(que)度
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(ce)溫度的******值。
鎧裝熱電偶熱響應時間
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。
鎧裝熱電偶熱響應時間不大于下表的規(gui)定:
熱響應時間T0.5S | 接殼式(shi) | 絕緣式 |
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
當周圍(wei)空(kong)氣溫度(du)為20±15℃,相對濕度(du)不(bu)大于80﹪時,絕(jue)緣(yuan)型鎧裝熱電(dian)偶(ou)(ou)的偶(ou)(ou)絲與外套管之(zhi)間的絕(jue)緣(yuan)電(dian)阻(zu)值應符(fu)合下表規定。
套(tao)管(guan)直徑(jing)mm | 試驗電壓V-D.C | 絕緣(yuan)電阻MΩ.m |
0.5~1.5 | 50±5 | ≥1000 |
>1.5 | 500±50 | ≥1000 |
型號表示(shi)
W | R | 規格(ge) | 內容 | ||||||
N | 鎳(nie)鉻(ge)-鎳(nie)硅(gui) | ||||||||
E | 鎳鉻-銅鎳 | ||||||||
C | 銅(tong)-銅(tong)鎳 | ||||||||
測 溫 元 件(jian) 材 料(liao) | K | ||||||||
鎧 裝 式 | - | 1 | 無固(gu)定裝置式 | ||||||
2 | 固定卡套(tao)螺(luo)紋 | ||||||||
3 | 可動卡套(tao)螺紋 | ||||||||
4 | 固定(ding)卡套法蘭 | ||||||||
5 | 可動卡套法蘭 | ||||||||
安 裝 固 定 形 式 | 0 | 無接線(xian)盒(he)式 | |||||||
2 | 防(fang)濺(jian)式 | ||||||||
3 | 防水式 | ||||||||
8 | 手(shou)柄式 | ||||||||
8 | 小接線盒式 | ||||||||
9 | 帶補償導線(xian) | ||||||||
接 線 盒 形(xing) 式 | 1 | 絕緣式 | |||||||
2 | 接殼式 | ||||||||
7 | 絕(jue)緣式(手柄式) | ||||||||
8 | 接殼式(手(shou)柄式) | ||||||||
工 作 端(duan) 形 式 | 3 | 3對 | |||||||
4 | 4對 | ||||||||
5 | 5對 | ||||||||
6 | 6對(dui) | ||||||||
多 對 式 | |||||||||
W | R | □ | K | - | □ | □ | □ | □ |