Common test methods for insulating and sheathing materials of electric cables . part 5 : methods specific to filling compounds . section one : drop - point - separation of oil - lower temperature brittleness - total acid number - absence of corrosive components - permittivity at 23 - d . c . resistivity at 23 and 100 电缆绝缘和护套材料通用试验方法第5部分:填充膏专用试验方法第1节:滴点-油分离-低温脆性-总酸值-腐蚀性- 23时的介电常数- 23和100时的直流电阻率