acoustical holography,声全息

    acoustical holography by electron-beam scanning,电子束扫描声全息

    acoustical holography by laser scanning,激光束扫描声全息

    acoustical holography by mechanical scanning,机械扫查声全息

    acoustical imaging by bragg diffraction,布拉格衍射声成像

    acoustical impedance method,声阻法

    acoustical lens,声透镜

    acoustically transparent pressure vessel,透声压力容器

    acquisition time,取数据时间

    actinometer,光能计；直接日射强度表；日射表

    (active)energy meter,（有功）电度表

    active gauge length,有效基长

    active gauge width,有效基宽

    active metal indicated electrode,活性金属指示电极

    active remote sensing,主动遥感

    active transducer[sensor],有源传感器

    activity,活度 activity coefficient,活度系数

    actual material calibration,实物校准

    actual time of observation,实际观测时间

    actual transformation ratio of voltage transformer,电压互感器的实际变化