GB/T 39750-2021.Technology requirements of DC arc-fault circuit protection for photovoltaic power system. 1范围 GB/T 39750规定了光伏发电系统直流电弧的基本规定、保护装置要求、保护方式

GB/T 39841-2021.Ultrasonic gas meters. 1范围 GB/T 39841规定了超声波燃气表(以下简称燃气表)的工作条件、技术要求、试验方法、检验规则、包装、运输和贮存等。 GB/T 39841适用于最大工作压力不超过50 kPa、最大流量不超过160 m3/h、准确

GB/T 39816-2021.Master alloy electrode for titanium and titanium alloy casting. 1范围 GB/T 39816规定了钛及钛合金铸造母合金电极的技术要求、试验方法、检验规则、标志.包装、运输、贮存及随行文件和订货单内容。 G

GB/T 39938-2021.Electric room heating一Underfloor heating-Performance characteristics-Definitions，method of testing, sizing and formula symbols. 1范围 GB

GB/T 39820-2021.Cerium bromide scintillator. 1范围 GB/T 39820规定了溴化铈闪烁体的术语和定义、技术要求、试验方法.检验规则.标志、包装.运输、贮存和随行文件。 GB/T 39820适用于测量核辐射的溴化铈闪烁体。 2规范性引用文 件 下列文件对

GB/T 28267.1-2021.Steel cord conveyor belts-Part1 : Design, dimensions and mechanical requirements for conveyor belts for general use. 1范围 GB/T 28267的

GB/T 39934-2021.Determination of volatile organic compounds from furniture products-Gas chromatography-mass spectrometry. 1范围 GB/T 39934规定了采用气相色谱质谱法进行

GB/T 39843-2021.Electronic characteristic measurements-Local critical current density and its distribution in large-area superconducting films. 1范围 GB

GB/T 39744-2021.General requirements of mechanical product electronic manual based on three-dimensional model. 1范围 GB/T 39744规定了基于三维模型的机械产品电子手册(以下简称电子

GB/T 39955-2021.Additive manufacturing-Materials-Powders of Nylon 12 and its composites for powder bed fusion. 1范围 GB/T 39955规定了粉末床熔融用尼龙12及其复合粉末的命名规则、