GB/T 13268-1991 Atmospheric air—Test dust standard sample—Loess dust

GB/T 5161-1985 Metallic powders—Determination of effective density—Liquid immersion method GB/T 5161-2014 Metallic powders—Determination of effective density—Liquid immersion method GB/T 6524-2003 Metallic powders-Determination of particle size distribution by gravitational sedimentation in a liquid and attenuation measurement GB/T 6900-2006 Chemical analysis of alumina-silica refractories GB/T 6900-2016 Chemical analysis of alumina-silica refractories GB/T 6900.1-1986 Fireclay and high-alumina refractories—Determination of loss content on ignition—Gravimetric method GB/T 6900.2-1986 Fireclay and high-alumina refractories—Determination of silicon dioxide content—Gravimetric-molybdenum blue photometric method GB/T 6900.3-1986 Fireclay and high-alumina refractories—Determination of iron oxide content—o-Phenanthroline photometric method GB/T 6900.4-1986 Fireclay and high-alumina refractories—Determination of aluminium oxide content—EDTA volumetric method GB/T 6900.5-1986 Fireclay and high-alumina refractories—Determination of titanium dioxide content—Hydrogen peroxide photometric method GB/T 6900.6-1986 Fireclay and high-alumina refractories—Determination of calcium oxide content—EDTA volumetric method GB/T 6900.7-1986 Fireclay and high-alumina refractories—Determination of magnesium oxide content—Xylidyl blue Ⅰ-CTAB photometric method GB/T 6900.8-1986 Fireclay and high-alumina refractories—Determination of calcium oxide and magnesium oxide content—Atomic absorption spectrophotometric method GB/T 6900.9-1986 Fireclay and high-alumina refractories—Determination of potassium oxide and sodium oxide content—Atomic absorption spectrophotometric method GB/T 6900.10-1986 Fireclay and high-alumina refractories—Determination of manganese oxide content—Ammonium persulfate photometric method GB/T 6900.11-1986 Fireclay and high-alumina refractories—Determination of phosphorous pentoxide content—Molybdenum blue photometric method GB/T 5161-2025 Metallic powder—Determination of effective density—Liquid immersion method GB/T 6900-2025 Chemical analysis of alumino-silicate refractories