可(ke)燃(ran)氣(qi)(qi)(qi)(qi)體(ti)(ti)探(tan)(tan)測(ce)器是對單一或多種(zhong)可(ke)燃(ran)氣(qi)(qi)(qi)(qi)體(ti)(ti)濃(nong)度作出響(xiang)應的(de)和(he)工(gong)(gong)業探(tan)(tan)測(ce)器。*主(zhu)要(yao)有催化式(shi)和(he)半導體(ti)(ti)式(shi)兩種(zhong)。使(shi)用煤氣(qi)(qi)(qi)(qi)、天然氣(qi)(qi)(qi)(qi)、液化石(shi)油氣(qi)(qi)(qi)(qi)的(de)飯店(dian)等工(gong)(gong)業場(chang)所(suo)主(zhu)要(yao)使(shi)用半導體(ti)(ti)型可(ke)燃(ran)氣(qi)(qi)(qi)(qi)體(ti)(ti)探(tan)(tan)測(ce)器。排(pai)放(fang)可(ke)燃(ran)氣(qi)(qi)(qi)(qi)體(ti)(ti)的(de)工(gong)(gong)業場(chang)所(suo)主(zhu)要(yao)采用催化式(shi)。下面分(fen)別(bie)介(jie)紹這兩種(zhong)類型的(de)實現原理：

　一(yi)個。催(cui)化式可燃氣體檢測儀

可燃(ran)氣體的濃度是(shi)由難(nan)熔金屬鉑(bo)絲(si)(si)加熱后(hou)的電(dian)阻變(bian)(bian)化(hua)決定的。當(dang)可燃(ran)氣體進入探測器后(hou)，會在鉑(bo)絲(si)(si)表(biao)面引起氧化(hua)反應（無焰燃(ran)燒），產生(sheng)(sheng)的熱量使鉑(bo)絲(si)(si)溫度升高，鉑(bo)絲(si)(si)電(dian)阻率發(fa)生(sheng)(sheng)變(bian)(bian)化(hua)。當(dang)鉑(bo)絲(si)(si)的溫度發(fa)生(sheng)(sheng)變(bian)(bian)化(hua)時，鉑(bo)絲(si)(si)的電(dian)阻率發(fa)生(sheng)(sheng)變(bian)(bian)化(hua)，檢測到的數據也發(fa)生(sheng)(sheng)變(bian)(bian)化(hua)。

　b. 半導體式(shi)可(ke)燃氣體探測器

可燃氣(qi)體的(de)(de)濃度(du)是通(tong)過半導體表面電阻的(de)(de)變化來測量的(de)(de)。在(zai)工(gong)作(zuo)狀(zhuang)態(tai)下(xia)，遇到可燃氣(qi)體時，半導體的(de)(de)阻值會下(xia)降，下(xia)降值與可燃氣(qi)體的(de)(de)濃度(du)有對應關系。

　 可(ke)燃氣體檢(jian)(jian)測(ce)(ce)(ce)儀由檢(jian)(jian)測(ce)(ce)(ce)和(he)檢(jian)(jian)測(ce)(ce)(ce)兩部分組成，具有檢(jian)(jian)測(ce)(ce)(ce)和(he)探測(ce)(ce)(ce)功能。

　可(ke)燃(ran)(ran)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)檢(jian)(jian)(jian)測(ce)(ce)(ce)儀(yi)檢(jian)(jian)(jian)測(ce)(ce)(ce)部分的(de)(de)(de)原理(li)是儀(yi)器(qi)(qi)的(de)(de)(de)傳感器(qi)(qi)采用(yong)檢(jian)(jian)(jian)測(ce)(ce)(ce)元件(jian)、固(gu)定電(dian)(dian)(dian)阻和調零(ling)電(dian)(dian)(dian)位器(qi)(qi)組成(cheng)檢(jian)(jian)(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)橋(qiao)(qiao)。該橋(qiao)(qiao)采用(yong)鉑(bo)絲(si)作為(wei)(wei)載體(ti)催(cui)化(hua)元件(jian)。通電(dian)(dian)(dian)后，鉑(bo)絲(si)溫(wen)度(du)(du)上升到(dao)工作溫(wen)度(du)(du)，空(kong)(kong)氣(qi)(qi)(qi)(qi)(qi)(qi)通過自(zi)然擴(kuo)散(san)或其(qi)他(ta)方式到(dao)達元件(jian)表(biao)面。當空(kong)(kong)氣(qi)(qi)(qi)(qi)(qi)(qi)中沒(mei)有可(ke)燃(ran)(ran)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)時，電(dian)(dian)(dian)橋(qiao)(qiao)輸(shu)出為(wei)(wei)零(ling)。當空(kong)(kong)氣(qi)(qi)(qi)(qi)(qi)(qi)中含有可(ke)燃(ran)(ran)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)擴(kuo)散(san)到(dao)檢(jian)(jian)(jian)測(ce)(ce)(ce)元件(jian)時，由于催(cui)化(hua)作用(yong)發(fa)(fa)生無焰燃(ran)(ran)燒，使檢(jian)(jian)(jian)測(ce)(ce)(ce)元件(jian)溫(wen)度(du)(du)升高(gao)，鉑(bo)絲(si)電(dian)(dian)(dian)阻增大，使電(dian)(dian)(dian)橋(qiao)(qiao)失去平衡(heng)，從(cong)而有電(dian)(dian)(dian)壓(ya)(ya)(ya)信(xin)(xin)號輸(shu)出，這個電(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)(de)(de)大小與可(ke)燃(ran)(ran)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)的(de)(de)(de)濃(nong)度(du)(du)成(cheng)正(zheng)比(bi)(bi)，信(xin)(xin)號被放(fang)大，由模擬轉換為(wei)(wei)數字，通過液晶顯示器(qi)(qi)顯示可(ke)燃(ran)(ran)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)的(de)(de)(de)濃(nong)度(du)(du)。檢(jian)(jian)(jian)測(ce)(ce)(ce)部分的(de)(de)(de)原理(li)是當被測(ce)(ce)(ce)可(ke)燃(ran)(ran)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)濃(nong)度(du)(du)過限定值(zhi)(zhi)時，放(fang)大后的(de)(de)(de)電(dian)(dian)(dian)橋(qiao)(qiao)輸(shu)出電(dian)(dian)(dian)壓(ya)(ya)(ya)與電(dian)(dian)(dian)路(lu)(lu)檢(jian)(jian)(jian)測(ce)(ce)(ce)設(she)定電(dian)(dian)(dian)壓(ya)(ya)(ya)，通過電(dian)(dian)(dian)壓(ya)(ya)(ya)比(bi)(bi)較器(qi)(qi)，方波發(fa)(fa)生器(qi)(qi)輸(shu)出一(yi)組方波信(xin)(xin)號，控制聲音，在光檢(jian)(jian)(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)路(lu)(lu)中，蜂鳴器(qi)(qi)發(fa)(fa)出連續的(de)(de)(de)聲音，發(fa)(fa)光二極管(guan)閃爍發(fa)(fa)出檢(jian)(jian)(jian)測(ce)(ce)(ce)信(xin)(xin)號。從(cong)可(ke)燃(ran)(ran)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)檢(jian)(jian)(jian)測(ce)(ce)(ce)儀(yi)的(de)(de)(de)原理(li)可(ke)以看出，如(ru)(ru)果有電(dian)(dian)(dian)磁干擾，會影響檢(jian)(jian)(jian)測(ce)(ce)(ce)信(xin)(xin)號，出現數據偏差；如(ru)(ru)果有碰撞或振動導致(zhi)設(she)備(bei)損壞，檢(jian)(jian)(jian)測(ce)(ce)(ce)將失敗；如(ru)(ru)果環境太(tai)潮濕或設(she)備(bei)進水(shui)，也可(ke)能(neng)損壞。造成(cheng)可(ke)燃(ran)(ran)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)檢(jian)(jian)(jian)測(ce)(ce)(ce)儀(yi)短路(lu)(lu)，或線路(lu)(lu)電(dian)(dian)(dian)阻值(zhi)(zhi)發(fa)(fa)生變化(hua)，導致(zhi)檢(jian)(jian)(jian)測(ce)(ce)(ce)失敗。