一、光纖測試儀的原理是什么
光纖測試儀是一種用于測量光(guang)(guang)(guang)纖網絡中光(guang)(guang)(guang)信(xin)號強度、損耗和(he)其他(ta)也關鍵(jian)參數的設備。它(ta)通(tong)過(guo)光(guang)(guang)(guang)源和(he)光(guang)(guang)(guang)探(tan)頭將光(guang)(guang)(guang)信(xin)號發送(song)和(he)接收(shou),并通(tong)過(guo)分析收(shou)到(dao)的信(xin)號來評估(gu)光(guang)(guang)(guang)纖網絡的性能。
光(guang)(guang)纖(xian)測(ce)(ce)試(shi)(shi)儀(yi)可(ke)以(yi)測(ce)(ce)量電(dian)(dian)阻(zu),其(qi)原(yuan)理(li)是通過光(guang)(guang)纖(xian)技術將被(bei)測(ce)(ce)電(dian)(dian)阻(zu)點點位的(de)(de)電(dian)(dian)信(xin)(xin)號轉換為光(guang)(guang)信(xin)(xin)號進(jin)行傳(chuan)(chuan)輸(shu),并(bing)(bing)利用(yong)光(guang)(guang)纖(xian)傳(chuan)(chuan)輸(shu)特性測(ce)(ce)量電(dian)(dian)阻(zu)值(zhi)。具體來說,光(guang)(guang)纖(xian)測(ce)(ce)試(shi)(shi)儀(yi)通過一對電(dian)(dian)極將電(dian)(dian)信(xin)(xin)號輸(shu)入到(dao)(dao)被(bei)測(ce)(ce)電(dian)(dian)阻(zu)上,然后根(gen)據歐姆(mu)定律,電(dian)(dian)流值(zhi)與電(dian)(dian)阻(zu)值(zhi)成正比關系,即(ji)I=U/R,其(qi)中(zhong)I為電(dian)(dian)流值(zhi),U為為電(dian)(dian)壓(ya)值(zhi),R為電(dian)(dian)阻(zu)值(zhi)。然后,通過測(ce)(ce)量電(dian)(dian)流值(zhi)和電(dian)(dian)壓(ya)值(zhi)就可(ke)以(yi)計(ji)算出電(dian)(dian)阻(zu)值(zhi)。主要(yao)是輸(shu)出固定的(de)(de)光(guang)(guang)源信(xin)(xin)號,將該信(xin)(xin)號通過光(guang)(guang)纖(xian)傳(chuan)(chuan)輸(shu)到(dao)(dao)需要(yao)測(ce)(ce)試(shi)(shi)的(de)(de)被(bei)測(ce)(ce)設備,并(bing)(bing)在傳(chuan)(chuan)輸(shu)過程中(zhong)測(ce)(ce)量光(guang)(guang)功率計(ji)接(jie)收到(dao)(dao)的(de)(de)光(guang)(guang)信(xin)(xin)號功率大小。
二、光纖測試儀由什么構成
光纖測試儀是用于評估光(guang)纖(xian)傳輸性能(neng)的(de)設備,主要(yao)由光(guang)源和光(guang)功率計兩部分組成。
光(guang)(guang)源(yuan)是產(chan)生光(guang)(guang)信號(hao)的(de)(de)裝置,常用的(de)(de)光(guang)(guang)源(yuan)有LED光(guang)(guang)源(yuan)、激光(guang)(guang)光(guang)(guang)源(yuan)、白熾燈光(guang)(guang)源(yuan)等。不同(tong)的(de)(de)光(guang)(guang)源(yuan)產(chan)生的(de)(de)光(guang)(guang)信號(hao)波長和功率(lv)有所不同(tong),根據(ju)具(ju)體測試的(de)(de)需求選擇相應的(de)(de)光(guang)(guang)源(yuan)。
光(guang)(guang)功率(lv)計是測試光(guang)(guang)信(xin)號(hao)功率(lv)大(da)小的裝置。它通過接收被測試設備(bei)傳輸(shu)過來的光(guang)(guang)信(xin)號(hao),并將(jiang)其轉換(huan)成電信(xin)號(hao)進(jin)行(xing)測量,從而(er)評估光(guang)(guang)纖(xian)傳輸(shu)的性能(neng)。光(guang)(guang)功率(lv)計常用的結(jie)構(gou)是PIN衰減器結(jie)構(gou),其優(you)點是反應時間(jian)快,頻寬較高,精度高。