GB/T 21649.1-2024 Chinese PDF (GB/T21649.1-2024) GB 10408-2025 20-2025_Chinese: Methods for chemical analysis

20-2025_Chinese: Methods for chemical analysis of tungsten concentrates - Part 20: Determination of mercury content - Solid sampling and direct mercury analysis method (Chinese: 钨精矿化学分析方法 第20部分：汞含量的测定 固体进样直接测定法)

English versions: GB/T 20845-2024

English versions: GB/T 20840

10-2024_Chinese: Terminology for telecommunication - Antenna (Chinese: 电信术语 天线)

2-2024_Chinese: Variable-frequency drive above 1 kV and not exceeding 35 kV - Part 2: Test methods (Chinese: 1 kV以上不超过35 kV的通用变频调速设备 第2部分：试验方法)

GB/T 21649.1-2024 Chinese PDF (GB/T21649.1-2024) GB 10408-2025 20-2025_Chinese: Methods for chemical analysisGB T 21649. 1 2024_Chinese: Particle size analysis Image analysis methods Part 1: Static image analysis methods (Chinese: 1) Note Careful: Text of PDF is in Chinese (not English). Delivery (PDF in Chinese): 2 working hours typically, ASAP English versions: GB T 21649. 1 2024