Home / Standards / GB/T 31253-2014 GB/T 31253-2014 Active Natural gas―Validation for gaseous reference materials―Direct measurement of calorific value and density 天然气 气体标准物质的验证 发热量和密度直接测量法 Standard Type GBT ICS 75.060 CCS E24 Status 现行 Issue Date 2014-12-05 Implementation 2015-05-01 Responsible Dept 国家标准委 Drafting Unit N/A