Method and apparatus for determining distribution of mass density
    5.
    发明授权
    Method and apparatus for determining distribution of mass density 失效
    用于确定质量密度分布的方法和装置

    公开(公告)号:US4975578A

    公开(公告)日:1990-12-04

    申请号:US339211

    申请日:1989-04-17

    CPC分类号: G01N23/04

    摘要: Distribution of mass density of paper or other materials is determined by irradiating a sample with a burst of electron beams from an electron gun. The intensity levels of electron beams emerging from said sample are detected by an areal detector located immediately behind the sample. These intensity levels are processed to derive distribution of mass density information for the sample. The electron beam detector may be a photographic film or a realtime electron beam detector assembly coupled to computer controlled digital data processing and displaying equipment.