檢測氣體的濃度依賴於氣體檢測變送器,傳感器是其核心部分,按照檢測原理的不同,主要分為金屬氧化物半導體式傳感器、催化燃燒式傳感器、定電位電解式氣體傳感器、迦伐尼電池式氧氣傳感器、紅外式傳感器、PID光離子化傳感器等,以下簡單闡述各種傳感器的原理及特點。
金屬氧化物半導體式傳感器
jinshuyanghuawubandaotishichuanganqiliyongbeiceqitidexifuzuoyong,gaibianbandaotidediandaolv,tongguodianliubianhuadebijiao,jifabaojingdianlu。youyubandaotishichuanganqiceliangshishouhuanjingyingxiangjiaoda,shuchuxianxingbuwending。jinshuyanghuawubandaotishichuanganqi,yinqifanyingshifenlingmin,gumuqianguangfanshiyongdelingyuweiceliangqitideweilouxianxiang。
催化燃燒式傳感器
催化燃燒式傳感器原理是目前最廣泛使用的檢測可燃氣體的原理之一,具有輸出信號線形好、指數可靠、價格便宜、無wu與yu其qi他ta非fei可ke燃ran氣qi體ti的de交jiao叉cha幹gan擾rao等deng特te點dian。催cui化hua燃ran燒shao式shi傳chuan感gan器qi采cai用yong惠hui斯si通tong電dian橋qiao原yuan理li,感gan應ying電dian阻zu與yu環huan境jing中zhong的de可ke燃ran氣qi體ti發fa生sheng無wu焰yan燃ran燒shao,使shi溫wen度du使shi感gan應ying電dian阻zu的de阻zu值zhi發fa生sheng變bian化hua,打da破po電dian橋qiao平ping衡heng,使shi之zhi輸shu出chu穩wen定ding的de電dian流liu信xin號hao,再zai經jing過guo後hou期qi電dian路lu的de放fang大da、穩定和處理最終顯示可靠的數值。
定電位電解式氣體傳感器
dingdianweidianjieshichuanganqishimuqianceduleixianchangzuiguangfanshiyongdeyizhongjishu,zaicifangmianguowaijishulingxian,yincicileichuanganqidadouyilaijinkou。dingdianweidianjieshiqitichuanganqidejiegou:在一個塑料製成的筒狀池體內,安裝工作電極、對(dui)電(dian)極(ji)和(he)參(can)比(bi)電(dian)極(ji),在(zai)電(dian)極(ji)之(zhi)間(jian)充(chong)滿(man)電(dian)解(jie)液(ye),由(you)多(duo)孔(kong)四(si)氟(fu)乙(yi)烯(xi)做(zuo)成(cheng)的(de)隔(ge)膜(mo),在(zai)頂(ding)部(bu)封(feng)裝(zhuang)。前(qian)置(zhi)放(fang)大(da)器(qi)與(yu)傳(chuan)感(gan)器(qi)電(dian)極(ji)的(de)連(lian)接(jie),在(zai)電(dian)極(ji)之(zhi)間(jian)施(shi)加(jia)了(le)一(yi)定(ding)的(de)電(dian)位(wei),使(shi)傳(chuan)感(gan)器(qi)處(chu)於(yu)工(gong)作(zuo)狀(zhuang)態(tai)。氣(qi)體(ti)與(yu)的(de)電(dian)解(jie)質(zhi)內(nei)的(de)工(gong)作(zuo)電(dian)極(ji)發(fa)生(sheng)氧(yang)化(hua)或(huo)還(hai)原(yuan)反(fan)應(ying),在(zai)對(dui)電(dian)極(ji)發(fa)生(sheng)還(hai)原(yuan)或(huo)氧(yang)化(hua)反(fan)應(ying),電(dian)極(ji)的(de)平(ping)衡(heng)電(dian)位(wei)發(fa)生(sheng)變(bian)化(hua),變(bian)化(hua)值(zhi)與(yu)氣(qi)體(ti)濃(nong)度(du)成(cheng)正(zheng)比(bi)。
迦伐尼電池式氧氣傳感器
隔膜迦伐尼電池式氧氣傳感器的結構:在塑料容器的一麵裝有對氧氣透過性良好的、厚10~30μm的聚四氟乙烯透氣膜,在其容器內側緊粘著貴金屬(鉑、黃金、銀等)陰電極,在容器的另一麵內側或容器的空餘部分形成陽極(用鉛、鎘等離子化傾向大的金屬)。用(yong)氫(qing)氧(yang)化(hua)鉀(jia)。氧(yang)氣(qi)在(zai)通(tong)過(guo)電(dian)解(jie)質(zhi)時(shi)在(zai)陰(yin)陽(yang)極(ji)發(fa)生(sheng)氧(yang)化(hua)還(hai)原(yuan)反(fan)應(ying),使(shi)陽(yang)極(ji)金(jin)屬(shu)離(li)子(zi)化(hua),釋(shi)放(fang)出(chu)電(dian)子(zi),電(dian)流(liu)的(de)大(da)小(xiao)與(yu)氧(yang)氣(qi)的(de)多(duo)少(shao)成(cheng)正(zheng)比(bi),由(you)於(yu)整(zheng)個(ge)反(fan)應(ying)中(zhong)陽(yang)極(ji)金(jin)屬(shu)有(you)消(xiao)耗(hao),所(suo)以(yi)傳(chuan)感(gan)器(qi)需(xu)要(yao)定(ding)期(qi)更(geng)換(huan)。目(mu)前(qian)國(guo)內(nei)技(ji)術(shu)已(yi)日(ri)趨(qu)成(cheng)熟(shu),完(wan)全(quan)可(ke)以(yi)國(guo)產(chan)化(hua)此(ci)類(lei)傳(chuan)感(gan)器(qi)。
紅外式傳感器
hongwaishichuanganqiliyonggezhongyuansuduimougetedingbochangdexishouyuanli,juyoukangzhongduxinghao,fanyinglingmin,duidaduoshutanqinghuahewudouyoufanying。danjiegoufuza,chengbengao。
PID光離子化氣體傳感器
PID由(you)紫(zi)外(wai)燈(deng)光(guang)源(yuan)和(he)離(li)子(zi)室(shi)等(deng)主(zhu)要(yao)部(bu)分(fen)構(gou)成(cheng),在(zai)離(li)子(zi)室(shi)有(you)正(zheng)負(fu)電(dian)極(ji),形(xing)成(cheng)電(dian)場(chang),待(dai)測(ce)氣(qi)體(ti)在(zai)紫(zi)外(wai)燈(deng)的(de)照(zhao)射(she)下(xia),離(li)子(zi)化(hua),生(sheng)成(cheng)正(zheng)負(fu)離(li)子(zi),在(zai)電(dian)極(ji)間(jian)形(xing)成(cheng)電(dian)流(liu),經(jing)放(fang)大(da)輸(shu)出(chu)信(xin)號(hao)。PID具有靈敏度高,無中毒問題,安全可靠等優點。
|