Home / Standards / GB/T 21938-2008 GB/T 21938-2008 Abolished Earth-moving machinery - Hydraulic excavator and backhoe loader boom-lowering control device - Requirements and tests 土方机械 液压挖掘机和挖掘装载机动臂下降控制装置 要求和试验 Standard Type GBT ICS 53.100 CCS P97 Status 废止 Issue Date 2008-06-03 Implementation 2009-01-01 Responsible Dept 中国机械工业联合会 Drafting Unit N/A