MT/T 428-2008 The flame-proof electric bell for coal mine

GB 14048.1-2006 Low-voltage switchgear and controlgear—Part 1:General rules GB 3836.1-2000 Electrical apparatus for explosive gas atmospheres—Part 1:General requirements GB 3836.2-2000 Electrical apparatus for explosive gas atmospheres—Part 2:Flameproof enclosure “d” GB 3836.3-2000 Electrical apparatus for explosive gas atmospheres—Part 3:Increased safety “e” GB 4208-1993 Degrees of protection provided by enclosure (IP code) GB/T 10111-1988 Methods for random sampling by utilizing dices of random number GB/T 10111-2008 Generation of random numbers and procedures applied to sampling inspection for product quality GB/T 191-2000 Packaging—Pictorial marking for handling of goods GB/T 191-2008 Packaging—Pictorial marking for handling of goods GB/T 228-2002 Metallic materials—Tensile testing at ambient temperature GB/T 228.1-2010 Metallic materials—Tensile testing—Part 1:Method of test at room temperature GB/T 228.1-2021 Metallic materials—Tensile testing—Part 1:Method of test at room temperature GB/T 228.2-2015 Metallic materials—Tensile testing—Part 2:Method of test at elevated temperature GB/T 228.3-2019 Metallic materials—Tensile testing—Part 3:Method of test at low temperature GB/T 228.4-2019 Metallic materials—Tensile testing—Part 4:Method of test in liquid helium GB/T 2423.4-1993 Basic environmental testing procedures for electric and electronic products—Test Db:Damp heat, cyclic GB/T 2423.4-2008 Environmental testing for electric and electronic products—Part 2:Test method—Test Db:Damp heat,cyclic(12 h+12 h cycle) MT/T 661-1997 General technical condition for electrical apparatus used underground mine MT/T 906-2002 GB/T 191-2025 Graphical symbols marking for handling and storage of packages