X射線(xian)儀，是一(yi)種用來(lai)產(chan)生X射線(xian)的設備。
X射(she)(she)(she)線(xian)(xian)(xian)(xian)儀(yi)(yi)可(ke)以(yi)(yi)分(fen)為(wei)(wei)工(gong)業用(yong)(yong)X射(she)(she)(she)線(xian)(xian)(xian)(xian)儀(yi)(yi)和(he)醫用(yong)(yong)X射(she)(she)(she)線(xian)(xian)(xian)(xian)儀(yi)(yi)。工(gong)業用(yong)(yong)X射(she)(she)(she)線(xian)(xian)(xian)(xian)儀(yi)(yi)可(ke)以(yi)(yi)按照產(chan)生(sheng)(sheng)射(she)(she)(she)線(xian)(xian)(xian)(xian)的(de)(de)(de)強度分(fen)硬(ying)射(she)(she)(she)線(xian)(xian)(xian)(xian)機(ji)和(he)軟射(she)(she)(she)線(xian)(xian)(xian)(xian)機(ji)。用(yong)(yong)于理(li)化檢(jian)測(ce)的(de)(de)(de)衍(yan)射(she)(she)(she)分(fen)析儀(yi)(yi)等屬于軟射(she)(she)(she)線(xian)(xian)(xian)(xian)，而用(yong)(yong)于大，厚材料的(de)(de)(de)檢(jian)測(ce)的(de)(de)(de)是硬(ying)射(she)(she)(she)線(xian)(xian)(xian)(xian)。硬(ying)射(she)(she)(she)線(xian)(xian)(xian)(xian)的(de)(de)(de)產(chan)生(sheng)(sheng)可(ke)以(yi)(yi)用(yong)(yong)高壓(ya)電(dian)的(de)(de)(de)辦法，如100Kv或(huo)300Kv的(de)(de)(de)電(dian)壓(ya)加到x射(she)(she)(she)線(xian)(xian)(xian)(xian)管字(zi)上，產(chan)生(sheng)(sheng)的(de)(de)(de)射(she)(she)(she)線(xian)(xian)(xian)(xian)可(ke)以(yi)(yi)穿(chuan)透(tou)5--50mm的(de)(de)(de)鋼板(ban)(ban)。而用(yong)(yong)電(dian)子加速器的(de)(de)(de)辦法可(ke)以(yi)(yi)產(chan)生(sheng)(sheng)穿(chuan)透(tou)100mm以(yi)(yi)上的(de)(de)(de)鋼板(ban)(ban)的(de)(de)(de)射(she)(she)(she)線(xian)(xian)(xian)(xian)。使用(yong)(yong)高壓(ya)電(dian)辦法的(de)(de)(de)機(ji)器可(ke)分(fen)為(wei)(wei)，便攜式，和(he)移動式（固(gu)定式）。
X射(she)線(xian)(xian)儀原理(li)、構造及發(fa)現(xian)(xian)：1895年德國物(wu)理(li)學(xue)家(jia)倫琴在研究陰(yin)極(ji)(ji)射(she)線(xian)(xian)管(guan)中(zhong)(zhong)氣(qi)(qi)體(ti)放(fang)電(dian)現(xian)(xian)象(xiang)時，用(yong)(yong)(yong)一(yi)只(zhi)嵌(qian)有兩個金(jin)屬(shu)電(dian)極(ji)(ji)(一(yi)個叫做陽極(ji)(ji)，一(yi)個叫做陰(yin)極(ji)(ji))的(de)(de)(de)密封玻(bo)(bo)璃管(guan)，在電(dian)極(ji)(ji)兩端(duan)加(jia)上幾(ji)萬伏(fu)的(de)(de)(de)高壓(ya)電(dian)，用(yong)(yong)(yong)抽(chou)氣(qi)(qi)機(ji)從(cong)玻(bo)(bo)璃管(guan)內抽(chou)出(chu)空氣(qi)(qi)。為了遮住高壓(ya)放(fang)電(dian)時的(de)(de)(de)光線(xian)(xian)(一(yi)種(zhong)(zhong)弧光)外(wai)泄，在玻(bo)(bo)璃管(guan)外(wai)面套上一(yi)層黑色紙板(ban)(ban)。他在暗室中(zhong)(zhong)進行(xing)這項實驗(yan)時，偶然(ran)發(fa)現(xian)(xian)距離玻(bo)(bo)璃管(guan)兩米遠的(de)(de)(de)地(di)方，一(yi)塊用(yong)(yong)(yong)鉑(bo)氰化鋇溶液浸(jin)洗過的(de)(de)(de)紙板(ban)(ban)發(fa)出(chu)明亮的(de)(de)(de)熒(ying)光。再進一(yi)步試(shi)驗(yan)，用(yong)(yong)(yong)紙板(ban)(ban)、木板(ban)(ban)、衣服及厚約兩千頁的(de)(de)(de)書(shu)，都遮擋不住這種(zhong)(zhong)熒(ying)光。更令人驚(jing)奇的(de)(de)(de)是(shi)(shi)，當(dang)用(yong)(yong)(yong)手去拿(na)這塊發(fa)熒(ying)光的(de)(de)(de)紙板(ban)(ban)時，競在紙板(ban)(ban)上看(kan)到了手骨的(de)(de)(de)影像。當(dang)時倫琴認(ren)定：這是(shi)(shi)一(yi)種(zhong)(zhong)人眼看(kan)不見、但能穿(chuan)透物(wu)體(ti)的(de)(de)(de)射(she)線(xian)(xian)。因無(wu)法(fa)解(jie)釋它(ta)的(de)(de)(de)原理(li)，不明它(ta)的(de)(de)(de)性質，故借用(yong)(yong)(yong)了數學(xue)中(zhong)(zhong)代表未(wei)知數的(de)(de)(de)“X”作為代號，稱為“X”射(she)線(xian)(xian)(或稱X射(she)線(xian)(xian)或簡稱X線(xian)(xian))。這就是(shi)(shi)X射(she)線(xian)(xian)的(de)(de)(de)發(fa)現(xian)(xian)與名稱的(de)(de)(de)由來。工業射(she)線(xian)(xian)機(ji)正是(shi)(shi)使用(yong)(yong)(yong)了這種(zhong)(zhong)特性，利(li)用(yong)(yong)(yong)高壓(ya)變壓(ya)器(qi)(qi)加(jia)在兩個金(jin)屬(shu)電(dian)極(ji)(ji)上的(de)(de)(de)高壓(ya)產生射(she)線(xian)(xian)。X射(she)線(xian)(xian)儀用(yong)(yong)(yong)于航天，石油(you)建(jian)設(she)(she)，天然(ran)氣(qi)(qi)管(guan)道，鍋爐，壓(ya)力容器(qi)(qi)等無(wu)損探傷中(zhong)(zhong)不可缺少的(de)(de)(de)設(she)(she)備。
