屏(ping)(ping)(ping)蔽(bi)(bi)層(ceng)為(wei)了均勻(yun)導電(dian)(dian)線芯和絕緣(yuan)電(dian)(dian)場，0.3/0.5KV；0.45/0.75KV；0.6/1.0KV；3/6kV及以上的(de)中高壓電(dian)(dian)力電(dian)(dian)線電(dian)(dian)纜(lan)(lan)一(yi)般都有(you)(you)導體屏(ping)(ping)(ping)蔽(bi)(bi)層(ceng)和絕緣(yuan)屏(ping)(ping)(ping)蔽(bi)(bi)層(ceng)，部(bu)分(fen)低壓電(dian)(dian)線電(dian)(dian)纜(lan)(lan)不(bu)設置屏(ping)(ping)(ping)蔽(bi)(bi)層(ceng)。屏(ping)(ping)(ping)蔽(bi)(bi)層(ceng)有(you)(you)半導電(dian)(dian)屏(ping)(ping)(ping)蔽(bi)(bi)和金屬屏(ping)(ping)(ping)蔽(bi)(bi)兩種(zhong)，電(dian)(dian)力電(dian)(dian)線電(dian)(dian)纜(lan)(lan)屏(ping)(ping)(ping)蔽(bi)(bi)層(ceng)有(you)(you)三個作用(yong)：

　　1、半(ban)導(dao)電(dian)(dian)屏(ping)蔽層通常設置在(zai)導(dao)電(dian)(dian)線芯的外(wai)表面(mian)和絕緣(yuan)層的外(wai)表面(mian)，分別稱(cheng)為內半(ban)導(dao)電(dian)(dian)屏(ping)蔽層和外(wai)半(ban)導(dao)電(dian)(dian)屏(ping)蔽層。半(ban)導(dao)電(dian)(dian)屏(ping)蔽層是由電(dian)(dian)阻率很低(di)且厚(hou)度(du)較薄的半(ban)導(dao)電(dian)(dian)材(cai)料構成(cheng)。

　　2、內半(ban)(ban)導電(dian)(dian)(dian)屏(ping)蔽層(ceng)是為了均勻線芯(xin)外(wai)(wai)表(biao)(biao)面電(dian)(dian)(dian)場，避免因導體表(biao)(biao)面不光滑以及線芯(xin)絞合產生(sheng)的氣隙而造成(cheng)導體和(he)絕緣(yuan)發(fa)生(sheng)局(ju)(ju)部放(fang)電(dian)(dian)(dian)。外(wai)(wai)半(ban)(ban)導電(dian)(dian)(dian)屏(ping)蔽層(ceng)與絕緣(yuan)層(ceng)外(wai)(wai)表(biao)(biao)面接觸很好(hao)，且與金屬(shu)護套(tao)等電(dian)(dian)(dian)位，避免因電(dian)(dian)(dian)線電(dian)(dian)(dian)纜絕緣(yuan)表(biao)(biao)面裂紋等缺(que)陷而與金屬(shu)護套(tao)發(fa)生(sheng)局(ju)(ju)部放(fang)電(dian)(dian)(dian)。

　　3、對于沒(mei)有金屬護套的(de)中(zhong)低壓電力(li)電線電纜，除(chu)了設置有半導電屏(ping)(ping)蔽層外，還(huan)要增加金屬屏(ping)(ping)蔽層。金屬屏(ping)(ping)蔽層通常由銅帶或銅絲繞(rao)包而成，主要起到(dao)屏(ping)(ping)蔽電場的(de)作用。

屏(ping)蔽(bi)電纜采用(yong)(yong)對絞、對屏(ping)、總屏(ping)（或(huo)三線組(zu)合、組(zu)屏(ping)蔽(bi)、組(zu)屏(ping)總屏(ping)）等結構形式，具(ju)有介質(zhi)損耗小(xiao)、傳(chuan)(chuan)輸(shu)傳(chuan)(chuan)號(hao)能(neng)力強、抗干(gan)擾性能(neng)好(hao)等特點，能(neng)可靠地(di)傳(chuan)(chuan)輸(shu)微弱的模擬(ni)信號(hao)，可廣泛(fan)地(di)應用(yong)(yong)于發電、冶金(jin)、石油、化(hua)工、輕紡等部(bu)門的檢測和控(kong)制用(yong)(yong)計算機系(xi)統或(huo)自動(dong)化(hua)裝置，以及一(yi)般(ban)的工業計算機上。