This standard provides a uniform test method for determining the ability of carbon materials to allow gas to pass through at room temperature, i.e., permeability. The core principle involves allowing clean, dry nitrogen to flow through a cylindrical specimen of specified dimensions under laminar flow conditions. Permeability is calculated by measuring the pressure difference across the specimen and the gas flow rate. To perform this test, a specialized carbon material permeability tester is required. The instrument system typically consists of a gas supply unit (such as a nitrogen cylinder), a pressure regulation device, a specimen cylinder with a built-in specimen holder and latex sealing sleeve, as well as components such as pressure gauges and flow meters for measuring pressure difference and flow rate. This method is also applicable for determining the permeability of refractory materials used in blast furnaces.