| 摘要 |
A radiation sensor provides on-line measurement of web MD/CD fiber orientation ratio, formation indexes of multiple spatial frequencies, and optical density as it relates to basis weight. A light source illuminates one side of a substrate to be measured. The radiation passing through the substrate is detected by a pair of detectors having fields of view along narrow strips which are perpendicular to each other. The combined field of view is scanned in a repetitive pattern traversing an area on the substrate to be analyzed. The detector outputs are processed to provide fiber orientation ratio, formation, and basis weight measurements. |
