PE空心陰極燈

發(fa)光原理

      空心陰(yin)(yin)極(ji)燈(deng)（hollow cathode lamp,HCL）是一種特殊形式的(de)(de)低(di)壓氣體放電(dian)(dian)(dian)(dian)(dian)光(guang)源，放電(dian)(dian)(dian)(dian)(dian)集中(zhong)于陰(yin)(yin)極(ji)空腔內(nei)。當在(zai)兩極(ji)之(zhi)間施加200V-500V電(dian)(dian)(dian)(dian)(dian)壓時(shi)(shi)，便(bian)產生輝(hui)光(guang)放電(dian)(dian)(dian)(dian)(dian)。在(zai)電(dian)(dian)(dian)(dian)(dian)場作用(yong)下，電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)在(zai)飛向陽(yang)極(ji)的(de)(de)途中(zhong)，與(yu)(yu)載氣原子(zi)(zi)碰撞(zhuang)并使(shi)之(zhi)電(dian)(dian)(dian)(dian)(dian)離(li)，放出(chu)二次電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)，使(shi)電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)與(yu)(yu)正(zheng)(zheng)離(li)子(zi)(zi)數目(mu)增加，以維持放電(dian)(dian)(dian)(dian)(dian)。正(zheng)(zheng)離(li)子(zi)(zi)從電(dian)(dian)(dian)(dian)(dian)場獲得動能(neng)。如(ru)果(guo)正(zheng)(zheng)離(li)子(zi)(zi)的(de)(de)動能(neng)足以克服金屬陰(yin)(yin)極(ji)表面的(de)(de)晶格能(neng)，當其撞(zhuang)擊在(zai)陰(yin)(yin)極(ji)表面時(shi)(shi)，就可以將原子(zi)(zi)從晶格中(zhong)濺(jian)(jian)射(she)(she)出(chu)來。除濺(jian)(jian)射(she)(she)作用(yong)之(zhi)外，陰(yin)(yin)極(ji)受熱也(ye)要導(dao)致(zhi)陰(yin)(yin)極(ji)表面元(yuan)素的(de)(de)熱蒸發。濺(jian)(jian)射(she)(she)與(yu)(yu)蒸發出(chu)來的(de)(de)原子(zi)(zi)進入空腔內(nei)，再與(yu)(yu)電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)、原子(zi)(zi)、離(li)子(zi)(zi)等(deng)發生第二類碰撞(zhuang)而受到激發，發射(she)(she)出(chu)相應元(yuan)素的(de)(de)特征的(de)(de)共振輻射(she)(she)。與(yu)(yu)此同(tong)時(shi)(shi)，HCL所發射(she)(she)的(de)(de)譜線中(zhong)還包含了(le)內(nei)充(chong)氣、陰(yin)(yin)極(ji)材(cai)料和(he)雜(za)質(zhi)元(yuan)素等(deng)譜線。

       因(yin)為燈內填充氣(qi)體壓(ya)(ya)力低，壓(ya)(ya)力變寬(kuan)很小(xiao)；陰極(ji)溫(wen)度(du)較低，熱(re)變寬(kuan)也很小(xiao)；同(tong)時(shi)，因(yin)為氣(qi)體密度(du)低，自吸(xi)變寬(kuan)也不存在(zai)。HCL基本(ben)滿足發射譜(pu)(pu)線的(de)(de)半寬(kuan)度(du)窄、譜(pu)(pu)線強度(du)大且穩定、譜(pu)(pu)線背景(jing)小(xiao)、操(cao)作方便和經久(jiu)耐用(yong)(yong)等銳線光源(yuan)的(de)(de)基本(ben)要求。并(bing)且，當采用(yong)(yong)較大的(de)(de)燈電(dian)流(liu)時(shi)，HCL所發射譜(pu)(pu)線半寬(kuan)度(du)變寬(kuan)和譜(pu)(pu)線強度(du)增高，此(ci)時(shi)檢測器的(de)(de)負高壓(ya)(ya)降低，吸(xi)光度(du)讀數穩定。

PE空心陰極燈

特點

      用于原子吸收的(de)配套光源，具有譜(pu)線發射(she)能量強、吸收靈敏度高(gao)、穩定性(xing)好、壽(shou)命長（大部(bu)分元(yuan)素都可達到(dao)5000mAh,低(di)熔(rong)點元(yuan)素可達3000mAh）、低(di)噪聲、低(di)漂(piao)移等特性(xing)。

       起輝(hui)電壓(ya)≤360V，基線(xian)漂移：預(yu)熱30min 在30min內≤1%，分析(xi)線(xian)背景≤1%，主分析(xi)線(xian)：發射強度(du)波動(dong)噪聲＜0.1%。能夠很好的匹配于國內外各品牌(pai)原子吸(xi)收光譜儀。

PE空心陰極燈   

使用注意(yi)事項

①注意(yi)極性不能接反(fan)。

②為了(le)使燈發光(guang)強度穩定，在工作(zuo)電(dian)流下預熱10-30min。

③燈長(chang)期不用，應定期點燃，一(yi)般在工(gong)作電流下(xia)預熱1h。

④長期擱(ge)置，燈(deng)內有(you)雜質(zhi)存在，可以(yi)采用反(fan)接去氣法(fa)。，顛倒電極用大電流點燈(deng)30min.