
金屬氧(yang)化物半導體式傳感器
金屬(shu)氧化(hua)物半(ban)導(dao)體(ti)式傳感器利用被測氣體(ti)的(de)吸(xi)附(fu)作用,改變半(ban)導(dao)體(ti)的(de)電導(dao)率,通(tong)過電流變化(hua)的(de)比(bi)較,激發報警(jing)電路。由(you)于半(ban)導(dao)體(ti)式傳感器測量時受環境(jing)影響較大,輸(shu)出線形不(bu)穩定。金屬(shu)氧化(hua)物半(ban)導(dao)體(ti)式傳感器,因其反應十分靈敏,故目前廣泛使用的(de)領域為測量氣體(ti)的(de)微漏(lou)現(xian)象。
催化燃燒式傳感器(qi)
催化(hua)燃(ran)(ran)燒(shao)式傳(chuan)感器(qi)原(yuan)(yuan)理是(shi)目(mu)前廣泛使(shi)(shi)用的(de)檢測可(ke)(ke)燃(ran)(ran)氣體的(de)原(yuan)(yuan)理之一(yi),具有輸出信(xin)號線形好、指數可(ke)(ke)靠、價(jia)格便宜、無與其他非可(ke)(ke)燃(ran)(ran)氣體的(de)交叉干擾(rao)等特點。催化(hua)燃(ran)(ran)燒(shao)式傳(chuan)感器(qi)采用惠斯(si)通電(dian)(dian)橋原(yuan)(yuan)理,感應電(dian)(dian)阻與環(huan)境(jing)中的(de)可(ke)(ke)燃(ran)(ran)氣體發生(sheng)無焰燃(ran)(ran)燒(shao),使(shi)(shi)溫度(du)使(shi)(shi)感應電(dian)(dian)阻的(de)阻值發生(sheng)變化(hua),打破(po)電(dian)(dian)橋平衡(heng),使(shi)(shi)之輸出穩定(ding)的(de)電(dian)(dian)流信(xin)號,再經過后期電(dian)(dian)路的(de)放大、穩定(ding)和處理終顯(xian)示可(ke)(ke)靠的(de)數值。
定電位(wei)電解式氣體傳感器
定(ding)電(dian)(dian)(dian)(dian)位(wei)電(dian)(dian)(dian)(dian)解(jie)式傳(chuan)(chuan)(chuan)感器是目前測毒(du)類現場廣(guang)泛(fan)使用(yong)的(de)(de)(de)一(yi)種技術(shu)(shu),在此(ci)(ci)方(fang)面(mian)外技術(shu)(shu)領,因此(ci)(ci)此(ci)(ci)類傳(chuan)(chuan)(chuan)感器大都依賴(lai)進口。定(ding)電(dian)(dian)(dian)(dian)位(wei)電(dian)(dian)(dian)(dian)解(jie)式氣(qi)(qi)體傳(chuan)(chuan)(chuan)感器的(de)(de)(de)結構:在一(yi)個塑料制成(cheng)的(de)(de)(de)筒狀(zhuang)池(chi)體內(nei),安裝(zhuang)工作電(dian)(dian)(dian)(dian)極(ji)、對(dui)電(dian)(dian)(dian)(dian)極(ji)和參比電(dian)(dian)(dian)(dian)極(ji),在電(dian)(dian)(dian)(dian)極(ji)之間(jian)充滿電(dian)(dian)(dian)(dian)解(jie)液,由多孔四(si)氟乙烯做成(cheng)的(de)(de)(de)隔膜(mo),在頂部封裝(zhuang)。前置放(fang)大器與(yu)傳(chuan)(chuan)(chuan)感器電(dian)(dian)(dian)(dian)極(ji)的(de)(de)(de)連接,在電(dian)(dian)(dian)(dian)極(ji)之間(jian)施加了一(yi)定(ding)的(de)(de)(de)電(dian)(dian)(dian)(dian)位(wei),使傳(chuan)(chuan)(chuan)感器處(chu)于工作狀(zhuang)態。氣(qi)(qi)體與(yu)的(de)(de)(de)電(dian)(dian)(dian)(dian)解(jie)質內(nei)的(de)(de)(de)工作電(dian)(dian)(dian)(dian)極(ji)發生(sheng)氧化(hua)(hua)或(huo)還原反應,在對(dui)電(dian)(dian)(dian)(dian)極(ji)發生(sheng)還原或(huo)氧化(hua)(hua)反應,電(dian)(dian)(dian)(dian)極(ji)的(de)(de)(de)平衡電(dian)(dian)(dian)(dian)位(wei)發生(sheng)變化(hua)(hua),變化(hua)(hua)值與(yu)氣(qi)(qi)體濃度成(cheng)正比。
迦伐尼電池式氧(yang)氣傳感器(qi)
隔膜迦伐(fa)尼(ni)電池(chi)式氧氣(qi)傳感(gan)器的(de)結構:在塑料容器的(de)一面(mian)裝有(you)對氧氣(qi)透(tou)過(guo)性良好的(de)、厚10~30μm的(de)(de)聚四氟乙烯透氣膜,在(zai)其容(rong)器(qi)(qi)內(nei)側(ce)緊粘著貴金屬(shu)(鉑、黃金、銀等(deng))陰(yin)電(dian)極,在(zai)容(rong)器(qi)(qi)的(de)(de)另一(yi)面內(nei)側(ce)或(huo)容(rong)器(qi)(qi)的(de)(de)空余部分形成(cheng)陽極(用鉛(qian)、鎘等(deng)離(li)子化(hua)傾向大的(de)(de)金屬(shu))。用氫氧化(hua)鉀(jia)。氧氣在(zai)通過(guo)電(dian)解質時在(zai)陰(yin)陽極發生(sheng)氧化(hua)還原反應,使陽極金屬(shu)離(li)子化(hua),釋放出(chu)電(dian)子,電(dian)流的(de)(de)大小與(yu)氧氣的(de)(de)多少成(cheng)正比,由于整個反應中陽極金屬(shu)有消(xiao)耗,所以傳(chuan)感器(qi)(qi)需要(yao)定期更(geng)換。目前內(nei)技術已(yi)日趨成(cheng)熟,*可以產化(hua)此類傳(chuan)感器(qi)(qi)。
紅外(wai)式傳感器(qi)
紅(hong)外式傳(chuan)感器利用各種元素對(dui)某個特定(ding)波長的吸(xi)收原理(li),具有抗中毒(du)性好,反(fan)應(ying)靈(ling)敏,對(dui)大多(duo)數碳氫(qing)化合物都有反(fan)應(ying)。但結(jie)構復雜,成本高。
PID光離子化氣(qi)體(ti)傳感器
PID由(you)紫外(wai)燈光(guang)源和離(li)子室(shi)等主要部分構成(cheng)(cheng),在(zai)離(li)子室(shi)有正(zheng)負(fu)電(dian)(dian)極,形成(cheng)(cheng)電(dian)(dian)場(chang),待測氣體(ti)在(zai)紫外(wai)燈的照射下(xia),離(li)子化,生(sheng)成(cheng)(cheng)正(zheng)負(fu)離(li)子,在(zai)電(dian)(dian)極間(jian)形成(cheng)(cheng)電(dian)(dian)流,經放大輸出信號。PID具有靈(ling)敏度高,無中毒問題,安全可靠等(deng)優點。