MT 428-1995 Dust-proof electric bell for coal mine

MT 428-2007 Dust-proof electric bell for coal mine

GB 998 GB 1497 GB 156-2003 Standard voltages GB/T 156-2007 Standard voltages GB/T 156-2017 Standard voltages 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 762-2002 Standard current ratings GB/T 1410-2006 Methods of test for volume resistivity and surface resistivity of solid electrical insulating materials 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) GB/T 2900.35-1998 Electrotechnical terminology electrical apparatus for explosive atmospheres GB/T 2900.35-2008 Electrotechnical terminology Equipment for explosive atmospheres GB/T 2900.35-2023 Electrotechnical terminology—Explosive atmospheres GB/T 3768-1996 Acoustics—Determination of sound power levels of noise sources using sound pressure—Survey method using an enveloping measurement surface over a reflecting plane GB/T 3768-2017 Acoustics—Determination of sound power levels and sound energy levels of noise sources using sound pressure—Survey method using an enveloping measurement surface over a reflecting plane GB 3836.1-2000 Electrical apparatus for explosive gas atmospheres—Part 1:General requirements GB 3836.1-2010 Explosive atmospheres—Part 1:Equipment—General requirements GB/T 3836.1-2021 Explosive atmospheres—Part 1:Equipment—General requirements GB 3836.2-2000 Electrical apparatus for explosive gas atmospheres—Part 2:Flameproof enclosure “d” GB 3836.2-2010 Explosive atmospheres—Part 2:Equipment protection by flameproof enclosures "d" GB/T 3836.2-2021 Explosive atmospheres—Part 2:Equipment protection by flameproof enclosures “d” GB/T 4942.2-1993 Degrees of protection provided by enclosures for low-voltage apparatus 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 11020-2005 Flammability of solid non-metallic materials when exposed to flame sources—List of test methods JB/T 834-1999 Tropical low-pressure electrical equipment technical requirements JB/T 4262-1992 Explosion-proof electrical rubber-insulated cable introduction device GB/T 191-2025 Graphical symbols marking for handling and storage of packages GB/Z 156-2025 Good practice for dynamic light scattering(DLS) measurements