标准空气 meaning in English

normal air
standard air

Voltage measurement by means of standard air gaps
高电压测量标准空气间隙
In march 2006 , dajin was appointed for one of the primary draft units for the building material industry standand of wall surface coating material with air purification function by national development and reform commission
06年3月，国家发改委指定大津公司为“国家建材行业标准空气净化功能墙面涂覆材料”主要起草单位。
Methods of testing refractory materials - investment casting shell mould systems - determination of permeability and standard air flow capacity at elevated temperatures - section 10 . 2 : determination of permeability and standard air flow capacity at elevated temperatures
耐火材料试验方法.熔模铸造外壳铸模系统.升温时透气性和标准空气流量的测定