China 'GB/T 23561.4-2009
' standard english version:
NATIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA
GB/T 23561.4-2009
Methods for determining the physical and mechanical properties of coal and rock - Part 4: Methods for calculating the porosity of coal and rock 煤和岩石物理力学性质测定方法 第4部分:煤和岩石孔隙率计算方法
Issued Date:2009-04-08
Implemented Date:2009-12-01
Issued by:
The Standardization Administration of the People's Republic of China