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UL 1666-2021裝在豎直礦井內(nèi)的高壓電纜和光纜火焰蔓延試驗標(biāo)準(zhǔn)
UL 1666-2021 Test for Flame Propagation Height of Electrical and Optical-Fiber Cables Installed Vertically in Shafts.pdf
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