蔽光性 meaning in English

opacity
opaqueness

Fire hazard testing - part 6 - 1 : smoke opacity ; general guidance
着火危险试验.第6 - 1部分:烟蔽光性.一般指南
Fire hazard testing - part 6 : guidance and test methods on the assessment of obscuration hazard of vision caused by smoke opacity from electrotechnical products involved in fires - section 30 : small scale static method - determination of smoke opacity - description of the apparatus
着火危险试验.第6部分:火中电工产品产生的烟雾蔽光性引起的视觉遮蔽危险的评定指南和试验方法.第30节:小规模静态试验法.烟蔽光性的测定.仪器说明